Meeting invitations to configured aliases are not treated properly

[tom-ch1]

Steps to reproduce

1. configure email system so that [email protected] and [email protected] arrive at the same mailbox
2. add an account for [email protected] in nextcloud mail
3. configure an alias [email protected] to your [email protected] account
4. send a meeting invitation from outlook to [email protected]

Expected behavior

The meeting invitation should be treated in the same way as if it were sent to [email protected]:

• there should be options to accept, decline etc.
• the invitation should be added to the calendar if accepted

Actual behavior

The meeting invitation is recognised as such, but:

• the following message is displayed: This message has an attached invitation but the invitation does not contain a participant that matches any configured mail account address
• There is not way to accept, decline etc. and no way to add the meeting to the calendar

Mail app version

5.1.6

Nextcloud version

31.0.4

Mailserver or service

local mailserver (exim and dovecot)

Operating system

debian

PHP engine version

PHP 8.2

Nextcloud memory caching

No response

Web server

Apache (supported)

Database

PostgreSQL

Additional info

No response

[kesselb]

Thanks for the issue 👍

We are aware that the current implementation, which shows the iMIP options only when the recipient matches, isn't ideal and leads to confusion. I guess it makes sense, similar to Thunderbird, to refine the logic and, if we are unable to find the right calendar, ask the user for it.

Related: https://github.com/nextcloud/mail/issues/10788

[st3iny]

The CalDAV backend not handles aliases correctly when processing iMip messages.

However, the Mail app still does not recognize them and will show an incorrect iMip box. The confusing warning message is still shown.

Workaround: Import the event into the calendar manually. Changes via iMip will then be processed correctly.

Note: The fix is only available on Nextcloud 32 so far. The backport to 31 is still pending.

cc @SebastianKrupinski

[SebastianKrupinski]

As per https://github.com/nextcloud/mail/pull/11915#issuecomment-3405179291 this should be fixed now

[kesselb]

This bug report explicitly mentions an alias on the mail side. I’d like to keep the issue open for now to clarify whether we want to make any additional changes. The recent updates only address extra email addresses added to the profile in Nextcloud. What I have in mind is a hint, maybe in the account settings, if the email of the account isn't listed as an additional email address in Nextcloud and probably a button to automatically add it or so.

[SebastianKrupinski]

This bug report explicitly mentions an alias on the mail side. I’d like to keep the issue open for now to clarify whether we want to make any additional changes. The recent updates only address extra email addresses added to the profile in Nextcloud. What I have in mind is a hint, maybe in the account settings, if the email of the account isn't listed as an additional email address in Nextcloud and probably a button to automatically add it or so.

A better solution is to automatically add the email address for the mail account and any aliases to the user profile.

Actually, using the mail providers to list all the extra email addresses in mail during enumeration, would be the cleanest, then you don't need to keep them in sync. They would be synced automatically.

[beccon4]

For me this is a long standing issue which - by incidence - now found a solution. I have a DIN email address with my complete name and an alias with my initials which I use e.g. to forward invitations respective events from my various client's corporate Outlook calendars carelessly crossing corners by using my short email which never worked. Frustrated I opened a couple of issues - falsely assuming the cause is the email's composition - even fruitlessly running into an argument with one of your senior staff :-). A propper documentation would have avoided all this. (best here in the issues) Using the long email address for forwarding is a good workaround until we can configure the aliases somewhere.

[beccon4]

It'd be helpful to always display an attached or embedded ics invitation - as an attachment - even if the addresses do not match. There could always be a mismatch due to forwarding etc. Now, Mail recognizes that we have an invitation but then suppresses the ics attachment - while other formats attached go through and display the download option. Very annoying.