Which MTA for Linode 96?
What would you recommend for this?
When it comes down to it, it's not so much the MTA that will affect your performance as the virus and spam filters you use with it. Clamav works great, but it's a hog on a machine with less memory. Same with spamassassin.
I did run qmail a number of years ago to do lists with ezmlm, and I liked it. It was really lightweight, and secure back in the days when sendmail exploits were pretty common. But it had a goofy license that made it difficult to package or something – I don't really remember.