On Tue 16 Aug 2016 at 18:35:06 -0400, Jeffrey Mark Siskind wrote: > qobi@upplysingaoflun>all+n cat /etc/mailname [...Long list snipped...] Exim uses /etc/mailname to qualify an unqualified address such as jeffrey or david. The file should contain a single line with the fully qualified domain name for the system. See mailname(5). exim4-config_files(5) describes how /etc/aliases is handled on Debian.