I have an Ubuntu 18.04 LTS server that at one point in time was set up (not by me) to run GNU mailman, using Postfix as the MTA.
I no longer run any mailinglists on this server, and have ‐ to the best of my ability ‐ tried to remove and purge Gnu mailman from the server by running these commands:
sudo apt remove mailman
sudo apt autoremove mailman
sudo apt purge mailman
sudo apt autoremove --purge mailman
This removes mailman and some (most?) configuration and data files, but when I look in the Postfix log (/var/log/mail.log), I get these about every five minutes:
[…]: error: open database /var/lib/mailman/data/aliases.db: No such file or directory
[…]: warning: hash:/var/lib/mailman/data/aliases is unavailable. open database /var/lib/mailman/data/aliases.db: No such file or directory
[…]: warning: hash:/var/lib/mailman/data/aliases: lookup of 'root' failed
I understand why I get them, since purging GNU mailman deleted all those files.
I am pretty sure that the program that requests these files is Postfix, as running:
sudo service postfix status
… produces the same three lines of errors and warnings. However, I am unable to figure out what it is that makes Postfix want to open these files.
Restarting postfix:
sudo systemctl restart postfix
… cleans out the errors, but only temporary. After about five minutes, they are back when I check status.
The question is this: How to I get rid of these errors and warnings (without reinstalling the no longer needed application)?
 
    