#994289 fail2ban: On start and stop, emails go to root@localhost like it was on Debian 10, but also to nonexistant addresses set and escape:

Package:
fail2ban
Source:
fail2ban
Submitter:
Olaf Zaplinski
Date:
2021-10-13 18:03:02 UTC
Severity:
normal
#994289#5
Date:
2021-09-15 08:22:38 UTC
From:
To:
Dear Maintainer,

please see this email bounce snippet:

Betreff	[Fail2Ban] roundcube: started on binky.tuxfriends.net
Von	root
An	root@localhost, set@binky.tuxfriends.net, escape@binky.tuxfriends.net
Datum	Heute 10:10
Hi,

The jail roundcube has been started successfully.

Regards,

Fail2Ban
#994289#10
Date:
2021-10-13 17:58:18 UTC
From:
To:
Hi Olaf,

I can't confirm this on my systems, and I suspect that your mail command
is something that doesn't understand "-E 'set escape'". Could you check
what your mail command points to?

Here it is bsd-mailx:

# ls -l /usr/bin/mail lrwxrwxrwx 1 root root 22 Aug  4  2012
/usr/bin/mail -> /etc/alternatives/mail
# ls -l /etc/alternatives/mail
lrwxrwxrwx 1 root root 18 Aug  4  2012 /etc/alternatives/mail ->
/usr/bin/bsd-mailx

Cheers,
Mike