nmail - ncurses mail

Linux	Mac

nmail is a terminal-based email client for Linux and macOS with a user interface similar to alpine / pine.

Features

• Support for IMAP and SMTP protocols
• Local cache using sqlite (optionally AES256-encrypted)
• Multi-threaded (email fetch and send done in background)
• Address book auto-generated based on email messages
• Viewing HTML emails (converted to text in terminal, or in external browser)
• Opening/viewing attachments in external program
• Simple setup wizard for Gmail and Outlook/Hotmail
• Familiar UI for alpine / pine users
• Compose message using external editor ($EDITOR)
• View message using external viewer ($PAGER)
• Saving and continuing draft messages
• Compose HTML emails using Markdown (see markdown_html_compose option)
• Email search
• Compose emails while offline
• Color customization
• Signature

Not Supported / Out of Scope

• Local mailbox downloaded by third-party application (OfflineIMAP, fdm, etc)
• Multiple email accounts in a single session
• Special handling for Gmail labels
• Threaded view

Usage

Usage:

nmail [OPTION]

Command-line Options:

-d, --confdir <DIR>
    use a different directory than ~/.nmail

-e, --verbose
    enable verbose logging

-ee, --extra-verbose
    enable extra verbose logging

-h, --help
    display this help and exit

-o, --offline
    run in offline mode

-p, --pass
    change password

-s, --setup <SERV>
    setup wizard for specified service, supported services: gmail,
    gmail-oauth2, outlook

-v, --version
    output version information and exit

-x, --export <DIR>
    export cache to specified dir in Maildir format

Configuration files:

~/.nmail/auth.conf
    configures custom oauth2 client id and secret

~/.nmail/main.conf
    configures mail account and general setings

~/.nmail/ui.conf
    customizes UI settings

~/.nmail/secret.conf
    stores saved passwords

Examples:

nmail -s gmail
    setup nmail for a gmail account

Supported Platforms

nmail is developed and tested on Linux and macOS. Current version has been tested on:

• macOS Big Sur 11.0
• Ubuntu 20.04 LTS

Build / Install

Linux

Dependencies Ubuntu

Required:

sudo apt install git cmake build-essential libetpan-dev libssl-dev libncurses-dev libxapian-dev libsqlite3-dev libsasl2-modules libmagic-dev uuid-dev

Optional (to view/compose HTML emails):

sudo apt install pandoc

Dependencies Fedora

Required:

sudo yum -y install cmake libetpan-devel openssl-devel ncurses-devel xapian-core-devel sqlite-devel cyrus-sasl-devel cyrus-sasl-plain file-devel libuuid-devel clang

Optional (to view/compose HTML emails):

sudo yum -y install pandoc

Dependencies Arch Linux

Required:

sudo pacman -Sy cmake make libetpan openssl ncurses xapian-core sqlite cyrus-sasl file uuid clang

Optional (to view/compose HTML emails):

sudo pacman -Sy pandoc

Dependencies Common Linux

Optional (for OAuth 2.0 support):

pip3 install -U requests

Source

git clone https://github.com/d99kris/nmail && cd nmail

Build

mkdir -p build && cd build && cmake .. && make -s

Install

sudo make install

macOS

Dependencies

Required:

brew install cmake libetpan openssl ncurses xapian sqlite libmagic ossp-uuid

Optional (for OAuth 2.0 support):

pip3 install -U requests

Optional (to view/compose HTML emails):

brew install pandoc

Source

git clone https://github.com/d99kris/nmail && cd nmail

Build

mkdir -p build && cd build && cmake .. && make -s

Install

make install

Getting Started

Gmail Password Authenticated Setup

Use the setup wizard to set up nmail for the account. Example (replace [email protected] with your actual gmail address):

$ nmail -s gmail
Email: [email protected]
Name: Firstname Lastname
Password:
Save password (y/n): y

Note: Refer to Gmail Prerequisites for enabling IMAP access and password authentication.

Gmail OAuth 2.0 Setup

Use the setup wizard to set up nmail for the account. Example:

$ nmail -s gmail-oauth2
Cache Encryption Password (optional):
Save password (y/n): y

Cache encryption password is optional, if not specified all local cache encryption will be disabled.

Note: Refer to Gmail Prerequisites for enabling IMAP access and obtaining OAuth 2.0 access.

Outlook (and Hotmail) Setup

Use the setup wizard to set up nmail for the account. Example (replace [email protected] with your actual outlook / hotmail address):

$ nmail -s outlook
Email: [email protected]
Name: Firstname Lastname
Password:
Save password (y/n): y

Other Email Providers

Run nmail once in order for it to automatically generate the default config file:

$ nmail

Then open the config file ~/.nmail/main.conf in your favourite text editor and fill out the required fields:

[email protected]
drafts=Drafts
imap_host=imap.example.com
imap_port=993
inbox=INBOX
name=Firstname Lastname
smtp_host=smtp.example.com
smtp_port=587
trash=Trash
[email protected]

Full example of a config file ~/.nmail/main.conf:

[email protected]
addressbook_encrypt=0
auth=pass
auth_encrypt=1
cache_encrypt=0
cache_index_encrypt=0
client_store_sent=0
downloads_dir=
drafts=Drafts
editor_cmd=
file_picker_cmd=
folders_exclude=
html_to_text_cmd=
html_viewer_cmd=
idle_fetch_flags=1
imap_host=imap.example.com
imap_port=993
inbox=INBOX
msg_viewer_cmd=
name=Firstname Lastname
network_timeout=30
pager_cmd=
parts_viewer_cmd=
prefetch_all_headers=1
prefetch_level=2
queue_encrypt=1
save_pass=1
send_hostname=1
sent=Sent
server_timestamps=0
smtp_host=smtp.example.com
smtp_port=587
smtp_user=
text_to_html_cmd=
trash=Trash
[email protected]
verbose_logging=0

address

The from-address to use. Required for sending emails.

addressbook_encrypt

Indicates whether nmail shall encrypt local address book cache or not. Enabling it has some performance impact when starting and exiting nmail (default disabled).

auth

Specifies whether nmail shall use password authentication (pass) or Gmail OAuth 2.0 authentication (gmail-oauth2).

auth_encrypt

Indicates whether nmail shall encrypt local OAuth 2.0 access token store (default enabled).

cache_encrypt

Indicates whether nmail shall encrypt local message cache or not. Enabling it has some performance impact when starting and exiting nmail, as well as when navigating to different folders (default disabled).

cache_index_encrypt

Indicates whether nmail shall encrypt local search index or not. Enabling it has some performance impact when starting and exiting nmail (default disabled).

client_store_sent

This field should generally be left 0. It indicates whether nmail shall upload sent emails to configured sent folder. Many email service providers (gmail, outlook, etc) do this on server side, so this should only be enabled if emails sent using nmail do not automatically gets stored in the sent folder.

downloads_dir

Specifies a custom downloads directory path to save attachments to, for example downloads_dir=~/Downloads. If not specified, the current working dir is used.

drafts

Name of drafts folder - needed if using functionality to postpone email editing.

editor_cmd

The field editor_cmd allows overriding which external editor to use when composing / editing an email using an external editor (Ctrl-E). If not specified, nmail will use the editor specified by the environment variable $EDITOR. If $EDITOR is not set, nmail will use nano.

file_picker_cmd

By default when using Ctrl-T to select attachment files, the nmail internal file picker is used. By specifying this paramater an external command may be used instead. The command must output selected file(s) separated by linebreaks, on stdout. One may use nnn by setting the parameter like this:

file_picker_cmd=TMP=$(mktemp); 2>&1 nnn -p ${TMP}; (cat ${TMP} | tr '\0' '\n' | uniq; rm ${TMP})

folders_exclude

This field allows excluding certain folders from being accessible in nmail and also from being indexed by the search engine. This is mainly useful for email service providers with "virtual" folders that are holding copies of emails in other folders. When using the setup-wizard to configure a Gmail account, this field will be configured to "[Gmail]/All Mail","[Gmail]/Important","[Gmail]/Starred". As an alternative to configuring this parameter for Gmail, folders can be excluded from IMAP access on server side. In Gmail web interface, navigate to "Settings", "See all settings", "Labels" and untick "Show in IMAP" for "Starred", "Important" and "All Mail".

html_to_text_cmd

This field allows customizing how nmail should convert HTML emails to text. If not specified, nmail checks if pandoc, w3m, lynx or elinks is available on the system (in that order), and uses the first found. The exact command used is one of:

• pandoc -f html -t plain+literate_haskell --wrap=preserve
• w3m -T text/html -I utf-8 -dump
• lynx -assume_charset=utf-8 -display_charset=utf-8 -nomargins -dump -stdin
• elinks -dump-charset utf-8 -dump

Note that while pandoc generally produces a better text-equivalent to an html email, it is also slower than the other tools. For usage on a lower spec'ed system, consider using any of the other conversion utilities instead.

html_viewer_cmd

This field allows overriding the external viewer used when viewing message as html and previewing messages composed using markdown. The viewer may be a terminal-based program, e.g. w3m -o confirm_qq=false. By default nmail uses open on macOS and xdg-open >/dev/null 2>&1 on Linux.

idle_fetch_flags

This parameter controls whether nmail shall fetch flags (unread/read) for current folder upon entering/exiting IMAP idle state (default enabled).

imap_host

IMAP hostname / address. Required for fetching emails.

imap_port

IMAP port. Required for fetching emails.

inbox

IMAP inbox folder name. Required for nmail to open the proper default folder.

msg_viewer_cmd

This field allows overriding the command used for externally viewing a message (.eml file) with W. By default nmail uses open on macOS and xdg-open >/dev/null 2>&1 on Linux.

name

Real name of sender. Recommended when sending emails.

network_timeout

Specify timeout for IMAP and SMTP operations in seconds. If using a very slow network connection and sending very large emails it may be necessary to increase this timeout. By setting it to 0 network operations will not time out. Default 30 seconds.

pager_cmd

The field pager_cmd allows overriding which external pager / text viewer to use when viewing an email using an external pager (E). If not specified, nmail will use the pager specified by the environment variable $PAGER. If $PAGER is not set, nmail will use less.

parts_viewer_cmd

This field allows overriding the external viewer used when viewing email parts and attachments. By default nmail uses open on macOS and xdg-open >/dev/null 2>&1 on Linux.

prefetch_all_headers

Determines whether nmail shall fetch headers for all messages when viewing a folder, or only the latest based on message uid. By disabling this option there is no guarantee folder message lists are sorted by timestamp, as only headers for the last messages stored/added in the folder will be retrieved from server. Also note that some other nmail features may operate in degraded mode when this setting is disabled. The ability to disable prefetching of all headers is mainly to encompass use-cases where one wants to minimize network usage, or use nmail without persistant cache. Default enabled.

prefetch_level

Messages are pre-fetched from server based on the prefetch_level config setting. The following levels are supported:

0 = no pre-fetching, messages are retrieved when viewed
1 = pre-fetching of currently selected message
2 = pre-fetching of all messages in current folder view (default)
3 = pre-fetching of all messages in all folders, i.e. full sync

With level 0-2 configured, pre-fetch level 3 - a single full sync - may be triggered at run-time by pressing s from the message list.

queue_encrypt

Indicates whether nmail shall encrypt local message offline queue or not (default enabled).

save_pass

Specifies whether nmail shall store the password(s) (default enabled).

send_hostname

Controls whether to send client hostname in SMTP authentication when sending outgoing emails. If disabled, nmail uses client local IP address.

sent

IMAP sent folder name. Used by nmail if client_store_sent is enabled to store copies of outgoing emails.

server_timestamps

Use server timestamps for messages, rather than the timestamp in the message header (default disabled).

smtp_host

SMTP hostname / address. Required for sending emails.

smtp_port

SMTP port. Required for fetching emails. Default 587.

smtp_user

The field smtp_user should generally be left blank, and only be specified in case the email account has different username and password for sending emails (or if one wants to use one email service provider for receiving and another for sending emails). If not specified, the configured user field will be used.

text_to_html_cmd

This field allows customizing how nmail should convert composed plain text markdown message to corresponding text/html part. If not specified, nmail checks if pandoc or markdown is available on the system (in that order), and uses the first found. The exact command used is one of:

• pandoc -s -f gfm -t html
• markdown

trash

IMAP trash folder name. Needs to be specified in order to delete emails.

user

Email account username for IMAP (and SMTP).

verbose_logging

Allows forcing nmail to enable specified logging level:

0 = info, warnings, errors (default)
1 = debug (same as `-e`, `--verbose` - enable verbose logging)
2 = trace (same as `-ee`, `--extra-verbose` - enable extra verbose logging)

Multiple Email Accounts

nmail does currently not support multiple email accounts (in a single session). It is however possible to run multiple nmail instances in parallel with different config directories (and thus different email accounts), but it will be just that - multiple instances - each in its own terminal. To facilitate such usage one can set up aliases for accessing different accounts, e.g.:

alias gm='nmail -d ${HOME}/.nmail-gm' # gmail
alias hm='nmail -d ${HOME}/.nmail-hm' # hotmail

Compose Editor

The built-in email compose editor in nmail supports the following:

Alt-Backspace  delete previous word
Alt-Delete     delete next word
Alt-Left       move the cursor backward one word
Alt-Right      move the cursor forward one word
Arrow keys     move the cursor
Backspace      backspace
Ctrl-C         cancel message
Ctrl-E         edit message in external editor
Ctrl-K         delete current line
Ctrl-N         toggle markdown editing
Ctrl-O         postpone message
Ctrl-R         toggle rich headers (bcc)
Ctrl-T         to select, from address book / from file dialog
Ctrl-V         preview html part (using markdown to html conversion)
Ctrl-X         send message
Delete         delete
Enter          new line
Page Up/Down   move the cursor page up / down

The email headers To, Cc and Attchmnt support comma-separated values, ex:

To      : Alice <[email protected]>, Bob <[email protected]>
Cc      : Chuck <[email protected]>, Dave <[email protected]>
Attchmnt: localpath.txt, /tmp/absolutepath.txt
Subject : Hello world

Attachment paths may be local (just filename) or absolute (full path).

Email Search

Press / in the message list view to search the local cache for an email. The local cache can be fully syncronized with server by pressing s. The search engine supports queries with "quoted strings", +musthave, -mustnothave, partialstring*, AND, OR, XOR and NOT.

Search terms may be prefixed by body:, subject:, from: or to: to search only specified fields. By default search query terms are combined with AND unless specified. Results are sorted by email timestamp.

Press < or Left to exit search results and go back to current folder message list.

Reporting Bugs

The preferred way of reporting bugs is by opening a Github issue. Providing a copy of ~/.nmail/log.txt when reporting the issue is preferred.

Different verbosity levels are supported. The default logging level is very brief, primarily to minimize performance overhead. However, when encountering issues and reporting bugs, it is generally preferred to provide logs produced in verbose mode. To enable verbose logging:

nmail --verbose

For certain low-level bugs it may be required to collect extra verbose logs. This produces very large log files with detailed information. The extra verbose logs typically contain actual email contents. Review and edit such logs to remove any private information before sharing. To enable extra verbose logging:

nmail --extra-verbose

Default logging verbosity can be configured with verbose_logging parameter in ~/.nmail/main.conf.

Finally, for issues where the logging above does not provide sufficient information, it may be necessary to run nmail through a debugger and capture detailed backtraces for all threads when an issue occurs. A simple utility is provided to run nmail through a debugger in the source package. Example usage:

./utils/debug-nmail.sh

The utility also supports passing arguments to nmail, enabling running nmail with a custom config directory, for example:

./utils/debug-nmail.sh -d ~/.nmail-hm

Once nmail exits, either normally or caused by a crash, the script outputs information on where to obtain the log file, for example:

gdb log file written to:
/tmp/nmail-gdb-5244.txt

Review the resulting log file and ensure there are no clear text passwords in it, before sharing it with others.

User Discussion Forums

For discussing nmail usage (including getting help from other users) a mailing list and a Telegram group are available.

Bug reports and feature requests should however be reported using Github issues to ensure they are properly tracked and get addressed.

Mailing List

Feel free to subscribe at www.freelists.org/list/nmail-users and once subscribed, send messages to nmail-users [at] freelists [dot] org

Telegram Group

The Telegram group is available at https://t.me/nmailusers

Security

nmail caches data locally to improve performance. Cached data can be encrypted by setting by setting cache_encrypt=1 in main.conf. Message databases are then encrypted using OpenSSL AES256-CBC with a key derived from a random salt and the email account password. Folder names are hashed using SHA256 (thus not encrypted).

Storing the account password (save_pass=1 in main.conf) is not secure. While nmail encrypts the password, the key is trivial to determine from the source code. Only store the password if measurements are taken to ensure ~/.nmail/secret.conf cannot by accessed by a third-party.

Configuration

Aside from main.conf covered above, the following files can be used to configure nmail.

~/.nmail/ui.conf

This configuration file controls the UI aspects of nmail. Default configuration file (platform-dependent defaults are left empty below):

attachment_indicator= 📎
bottom_reply=0
cancel_without_confirm=0
colors_enabled=1
compose_backup_interval=10
compose_line_wrap=0
delete_without_confirm=0
full_header_include_local=0
help_enabled=1
invalid_input_notify=1
key_back=,
key_backward_kill_word=
key_backward_word=
key_cancel=KEY_CTRLC
key_compose=c
key_compose_copy=C
key_delete=d
key_delete_line=KEY_CTRLK
key_export=x
key_ext_editor=KEY_CTRLE
key_ext_html_preview=KEY_CTRLV
key_ext_html_viewer=v
key_ext_msg_viewer=w
key_ext_pager=e
key_filter_show_current_date=3
key_filter_show_current_name=4
key_filter_show_current_subject=5
key_filter_show_has_attachments=2
key_filter_show_unread=1
key_filter_sort_reset=`
key_find=/
key_find_next=?
key_forward=f
key_forward_word=
key_goto_folder=g
key_import=i
key_jump_to=j
key_kill_word=
key_move=m
key_next_msg=n
key_next_page=KEY_NPAGE
key_open=.
key_othercmd_help=o
key_postpone=KEY_CTRLO
key_prev_msg=p
key_prev_page=KEY_PPAGE
key_quit=q
key_refresh=l
key_reply_all=r
key_reply_sender=R
key_rich_header=KEY_CTRLR
key_save_file=s
key_search=/
key_search_current_name=-
key_search_current_subject==
key_search_show_folder=\
key_select_all=a
key_select_item=KEY_SPACE
key_send=KEY_CTRLX
key_sort_date=#
key_sort_has_attachments=@
key_sort_name=$
key_sort_subject=%
key_sort_unread=!
key_sync=s
key_to_select=KEY_CTRLT
key_toggle_full_header=h
key_toggle_markdown_compose=KEY_CTRLN
key_toggle_text_html=t
key_toggle_unread=u
localized_subject_prefixes=
markdown_html_compose=0
new_msg_bell=1
persist_file_selection_dir=1
persist_find_query=0
persist_folder_filter=1
persist_search_query=0
persist_selection_on_sortfilter_change=1
persist_sortfilter=1
plain_text=1
postpone_without_confirm=0
quit_without_confirm=1
respect_format_flowed=1
rewrap_quoted_lines=1
search_show_folder=0
send_without_confirm=0
show_embedded_images=1
show_progress=1
show_rich_header=0
signature=0
tab_size=8
terminal_title=
unread_indicator=N

attachment_indicator

Controls which character to indicate that an email has attachments (default:  📎). For a more compact and plain layout one can use an ascii character and omit the leading space character, example: +.

bottom_reply

Controls whether to reply at the bottom of emails (default disabled).

cancel_without_confirm

Allow canceling email compose without confirmation prompt (default disabled).

colors_enabled

Enable terminal color output (default enabled).

compose_backup_interval

Specify interval in seconds for local backups during compose (default 10). If the system running nmail is unexpectedly shutdown while user is composing an email, then upon next nmail startup any backuped compose message will be automatically uploaded to the draft folder. Setting this parameter to 0 disables local backups.

compose_line_wrap

Specify how nmail shall wrap lines in outgoing emails. Supported options:

0 = none (default)
1 = using format=flowed
2 = hardwrap at 72 chars width

delete_without_confirm

Allow deleting emails (moving to trash folder) without confirmation prompt (default disabled).

full_header_include_local

While viewing full headers (by pressing h) nmail displays RFC 822 headers by default. This parameter allows enabling nmail to also display local / internal header fields, such as server timestamp. Default disabled.

help_enabled

Show supported keyboard shortcuts at bottom of screen (default enabled).

invalid_input_notify

Notify user when unsupported keyboard shortcuts are input (default enabled).

key_

Keyboard bindings for various functions (default see above). The keyboard bindings may be specified in the following formats:

• Ncurses macro (ex: KEY_CTRLK)
• Hex key code (ex: 0x22e)
• Octal key code sequence (ex: \033\177)
• Plain-text lower-case ASCII (ex: r)

Octal key code sequence for a key combination can be determined for example using the command sed -n l and pressing the combination, e.g. alt-left and then enter. The keycode for non-printable keys is then displayed in octal format in the terminal, for example:

\033b$

The trailing $ shall be ignored, and to comply with nmail config required input format, the printable b needs to be converted to octal format. A quick lookup using man ascii shows b is 142 in octal format. The resulting key code to use in the config file is \033\142.

localized_subject_prefixes

Email subjects are normalized (stripped of re:, fwd:) when sorting emails by subject, and when replying to, or forwarding an email. By default only the English prefixes re and fwd? (regex for fwd and fw) are removed. This parameter allows extending the removal to other localized prefixes. Example configuration for a Swedish user:

localized_subject_prefixes=sv,vb

For a French user:

localized_subject_prefixes=ref,tr

For a German user:

localized_subject_prefixes=aw,wg

markdown_html_compose

Default value for each new email, whether nmail shall enable markdown HTML compose. I.e. whether nmail shall generate a text/html message part based on processing the composed message as Markdown, when sending sending emails from nmail. This can be overridden on a per-email basis by pressing CTRL-N when editing an email (default disabled).

new_msg_bell

Indicate new messages with terminal bell (default enabled).

persist_file_selection_dir

Determines whether file selection view shall remember previous directory (default enabled).

persist_find_query

Controls whether to start with previous find query when performing repeated find queries (default disabled).

persist_folder_filter

Determines whether to persist move-to-folder list filter (default enabled).

persist_search_query

Controls whether to start with previous search query when performing repeated search queries (default disabled).

persist_selection_on_sortfilter_change

Determines whether to keep current message list selection when filtering/sorting mode is changed (default enabled).

persist_sortfilter

Specifies whether each folder listing shall persist its filtering/sorting mode (default enabled).

plain_text

Determines whether showing plain text (vs. html converted to text) is preferred. If the preferred email part is not present, nmail automatically attempts to show the other. This option can be re-configured at run-time by pressing t when viewing an email (default enabled).

postpone_without_confirm

Allow postponing email compose without confirmation prompt (default disabled).

quit_without_confirm

Allow exiting nmail without confirmation prompt (default enabled).

respect_format_flowed

Specify whether nmail shall respect email line wrapping of format=flowed type (default enabled).

rewrap_quoted_lines

Control whether nmail shall rewrap quoted lines (default enabled).

search_show_folder

Determines whether folder name should be shown in search results. This option can be re-configured at run-time by pressing \ when viewing search results (default disabled).

send_without_confirm

Allow sending email during compose without confirmation prompt (default disabled).

show_embedded_images

Determines whether to show embedded images in text/html part when viewing it using external viewer; press right arrow when viewing a message to go to parts view, and then select the text/html part and press right arrow again (default enabled).

show_progress

Specify how nmail shall show progress indication when fetching or indexing emails. Supported options:

0 = disabled
1 = show floating point percentage (default)
2 = show integer percentage

show_rich_header

Determines whether to show rich headers (bcc field) during email compose. This option can be re-configured in run-time by pressing CTRL-R when composing an email (default disabled).

signature

Determines whether to suffix emails with a signature (default disabled). When enabled, nmail will use ~/.nmail/signature.txt if present, or otherwise use ~/.signature for signature plain text content. When composing markdown formatted emails, nmail will use ~/.nmail/signature.html if present, for the html part, and otherwise simply convert the plain text signature to html.

Note: For custom html signature to work properly, the plain text signature should not be present more than once in the composed message, thus a very short plain text signature may not be ideal.

Example signature files: signature.txt, signature.html

tab_size

Tabs are expanded to spaces when viewed in nmail. This parameter controls the space between tab stops (default 8).

terminal_title

Specifies custom terminal title, ex: terminal_title=nmail - [email protected].

unread_indicator

Controls which character to indicate that an email is unread (default: N). For a more graphical interface, an emoji such as ✉ can be used.

~/.nmail/colors.conf

This configuration file controls the configurable colors of nmail. For this configuration to take effect, colors_enabled=1 must be set in ~/.nmail/ui.conf.

Example color config files are provided in /usr/local/share/nmail/themes and can be used by overwriting ~/.nmail/colors.conf.

Htop style theme

This color theme is similar to htop's default, see screenshot below with nmail and htop.

To use this config:

cp /usr/local/share/nmail/themes/htop-style.conf ~/.nmail/colors.conf

Manual configuration

Alternatively one may manually edit colors.conf. Colors may be specified using standard palette names (black, red, green, yellow, blue, magenta, cyan, white, gray, bright_red, bright_green, bright_yellow, bright_blue, bright_magenta, bright_cyan and bright_white) or using integer palette numbers (0, 1, 2, etc).

To use default terminal color, leave the color empty or set it to normal. To use inverted / reverse color set both fg and bg values to reverse.

For terminals supporting custom palettes it is also possible to specify colors using six digit hex format with 0x prefix, e.g. 0xa0a0a0. For each item background _bg and foreground _fg can be specified. Default configuration file:

color_dialog_bg=reverse
color_dialog_fg=reverse
color_help_desc_bg=
color_help_desc_fg=
color_help_keys_bg=reverse
color_help_keys_fg=reverse
color_highlighted_text_bg=reverse
color_highlighted_text_fg=reverse
color_quoted_text_bg=
color_quoted_text_fg=gray
color_regular_text_bg=
color_regular_text_fg=
color_selected_item_bg=
color_selected_item_fg=gray
color_top_bar_bg=reverse
color_top_bar_fg=reverse

color_dialog

User prompt dialogs and notifications at bottom of the screen, just above the help bar.

color_help_desc

Help shortcut description texts at bottom of the screen, i.e. Compose in C Compose.

color_help_keys

Help shortcut key binding texts at bottom of the screen, i.e. C in C Compose.

color_highlighted_text

Highlighted text, such as current message in message view, current folder in folder list, text strings found in message find, etc.

color_quoted_text

Quoted message text (lines starting with >).

color_regular_text

Default text color.

color_selected_item

Selected messages in message list view.

color_top_bar

Top / title bar.

~/.nmail/auth.conf

This configuration file allows users to set up custom OAuth 2.0 client id and client secret. If not specified, nmail uses its own application id and secret. Default configuration file:

oauth2_client_id=
oauth2_client_secret=

oauth2_client_id

Custom OAuth 2.0 client id.

oauth2_client_secret

Custom OAuth 2.0 client secret.

Email Service Providers

Gmail Prerequisites

Gmail prevents IMAP access by default.

In order to enable IMAP access go to the Gmail web interface - typically mail.google.com - and navigate to Settings -> Forwarding and POP/IMAP -> IMAP access and select: Enable IMAP

Password Authentication

Gmail prevents password authentication by default. To enable password-authenticated IMAP access, one must either set up an "app password" or enable "less secure app access".

To set up an "app password", navigate to https://myaccount.google.com/apppasswords and select app "Mail" and an appropriate device, e.g. "Mac", then click Generate.

To enable "less secure app access", go to myaccount.google.com/security and under Less secure app access click Turn on access (not recommended).

OAuth 2.0 Authentication

Google OAuth 2.0 application review has not yet been requested for nmail, and as such users need to request an invitation to use this. Please send an email to d99kris at gmail dot com with subject nmail google oauth2 invite from the google account address you would like to be invited.

Alternatively a user may set up their own OAuth 2.0 application with Google and configure ~/.nmail/auth.conf accordingly.

Accessing Email Cache using Other Email Clients

The nmail message cache may be exported to the Maildir format using the following command:

nmail --export ~/Maildir

A basic ~/.muttrc config file for reading the exported Maildir in mutt:

set mbox_type=Maildir
set spoolfile="~/Maildir"
set folder="~/Maildir"
set mask=".*"

Note: nmail is not designed for working with other email clients, this export option is mainly available as a data recovery option in case access to an email account is lost, and one needs a local Maildir archive to import into a new email account. Such import is not supported by nmail, but is supported by some other email clients, like Thunderbird.

Technical Details

Third-party Libraries

nmail is implemented in C++. Its source tree includes the source code from the following third-party libraries:

• apathy - Copyright 2013 Dan Lecocq - MIT License
• cereal - Copyright 2014 Randolph Voorhies, Shane Grant - BSD-3 License
• cxx-prettyprint - Copyright 2010 Louis Delacroix - Boost License
• cyrus-imap - Copyright 1994-2000 Carnegie Mellon University - BSD-3 License
• sqlite_modern_cpp - Copyright 2017 aminroosta - MIT License

Code Formatting

Uncrustify is used to maintain consistent source code formatting, example:

uncrustify -c etc/uncrustify.cfg --replace --no-backup src/*.cpp src/*.h

License

nmail is distributed under the MIT license. See LICENSE file.

Keywords

alternative to alpine, command line, console-based, email client, linux, macos, ncurses, terminal-based.