I do web development and one of the things I have to have running locally is a mail server that sends the email generated by the websites I work on. To be honest I know only a bit about mail servers and try to keep out of that. I do know of two very popular ones: Sendmail and Postfix. They’re both available in Ubuntu. I tried Sendmail first since I have longer relationship with the name, not that I had any reason to think it would be best. It installed and worked fine. However, suddenly my startup time was about 30 seconds longer and it was pausing on the Sendmail startup.
I wasn’t sure if I wanted to try Postfix so I called one of the company IT guys and they said that both mail servers are good. Postfix can be much more painful to configure but does start faster. He also added that if I didn’t need to customize it (I don’t), Postfix should be easy. It was. In both cases I just installed them in Synaptic- no configuration at all. But with Postfix, it was speedier as promised.
Make sure you ‘Mark Packages for Complete Removal’ in Synaptic if you’re removing Sendmail. I had errors for several days after because I just marked for removal and some stuff hung around.