$Conf{EMailFromUserName} is overridden by "auto_from on" in /etc/msmtprc

[toggoboge]

I am running the BackupPC v4.3.1 version of the container.

BTW, below I have obscured my domain as 'mydomain.com'.

$Conf{EMailFromUserName} is overridden by "auto_from on" in /etc/msmtprc, meaning the configured from-address is not used in outgoing emails.

Using SMTP_HOST & SMTP_MAIL_DOMAIN environment variables, I have configured the backuppc container to send emails via a local SMTP relay container (docker pull namshi/smtp).

I've created a Gmail account, [email protected], for use by the SMTP relay container. The Gmail account has also been setup with an alias, [email protected], and emails sent by a small python script from this address via my local SMTP relay are successfully received as coming from [email protected].

In the backuppc container, I have set $Conf{EMailFromUserName} to [email protected].

When I try to send a test email to [email protected] from inside the container, I see the following:

bash-5.0$ /usr/local/BackupPC/bin/BackupPC_sendEmail -u [email protected]
Sending test email using /usr/sbin/sendmail -t -f [email protected]

This successfully sends emails via my local SMTP relay. However, the mails are always received as coming from [email protected].

In spite of [email protected] being used on the sendmail command-line, I see the following in the headers:

From: [email protected] X-Google-Original-From: [email protected]

Gmail is not honouring the from-address because [email protected] has permission to send emails from [email protected], but not from [email protected].

I think this is happening because the "auto_from on" setting in /etc/msmtprc is causing msmtp to generate the from-address from the Linux username, 'backuppc' in this case. This causes the configured $Conf{EMailFromUserName} to be overridden, and [email protected] is used as the from-address instead of [email protected].

Manually changing "auto_from on" to "auto_from off" in /etc/msmtprc has fixed this for me (at least for test emails - I haven't yet checked other emails auto-sent by BackupPC), and the test email sent by the BackupPC_sendEmail command above, is now received by [email protected] with the from-address is correctly set to [email protected].

[toggoboge]

Oh, if you do decide to update entrypoint.sh to address this, it'd be nice to have an environment variable that allows users to enable msmtp logging, perhaps defaulting the logfile to /home/backuppc/msmtp.log if no path is provided. As I was changing it by hand anyhow, I've also modified /etc/msmtprc to include this line:

logfile /home/backuppc/msmtp.log

[adferrand]

Hello @toggoboge! Just to let you know that I saw your issue and did not forgot it. I will handle it as soon as I have some time.

[toggoboge]

Thanks. Maybe /var/log is a better location for a logfile.

[adferrand]

Hello @toggoboge, I finally got the time to handle this issue.

So, I improved the logic to fit the usecase you described here. Basically:

• all logs from msmtp are now stored in /var/log/msmtp.log, and also in supervisord stdout. I hope this will help a lot to debug mail issues
• also, when SMTP_MAIL_DOMAIN is empty (the default), msmtp does not try to rewrite the envelope-from in mails generated by backuppc. So $Conf{EMailFromUserName} will be used, not overwritten. If SMTP_MAIL_DOMAIN is set, the envelope-from will be overwritten to USER@SMTP_MAIL_DOMAIN, like before.

[toggoboge]

Thanks Adrien. Cheer, Brian

On Sun, Mar 1, 2020 at 4:56 PM Adrien Ferrand [email protected] wrote:

Hello @toggoboge https://github.com/toggoboge, I finally got the time to handle this issue.

So, I improved the logic to fit the usecase you described here. Basically:

• all logs from msmtp are now stored in /var/log/msmtp.log, and also in supervisord stdout. I hope this will help a lot to debug mail issues
• also, when SMTP_MAIL_DOMAIN is empty (the default), msmtp does not try to rewrite the envelope-from in mails generated by backuppc. So $Conf{EMailFromUserName} will be used, not overwritten. If SMTP_MAIL_DOMAIN is set, the envelope-from will be overwritten to USER@SMTP_MAIL_DOMAIN, like before.

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