Postfix is my favourite MTA for reasons I’ll not go into at the moment. It’s much better than sendmail.
Recently there has been yet another sendmail vulnerability, but I didn’t care because I use Postfix. Wietse Venema, the author of Postfix, did care. He could have said "sendmail sucks; use Postfix", but instead he wrote a patch for Postfix to remove the sendmail exploit from messages before they reach sendmail. Kudos.