It has bothered me for years that with every new Debian installation, a full MTA (Mail Transport Agent) was installed even if I had no desire to use the machine as a mail server. The MTA was necessary to satisfy package dependencies, though. I ended up with exim (which took forever to load during boot on some machines) and others (which seemed to run memory-heavy background stuff that slowed down the entire system). Removing one required installing another…
Debian – Using an MTA to Solve Dependencies
debiandependenciesmta
Best Answer
The solution is a dummy MTA, already provided with Debian Linux. It is called lsb-invalid-mta. Quoting the package description:
Thanks to the dependency resolver within aptitude for suggesting the removal of whatever big MTA and suggesting
lsb-invalid-mta
.