I have an old server that I need to migrate. It uses exim4 and pipes email to programs for certain addresses, and needs to send out automated email for forgotte

I have an old server that I need to migrate. It uses exim4 and pipes email to programs for certain addresses, and needs to send out automated email for forgotten passwords, etc. Is it worth moving to Postfix or something better? This is the part of the migration I look forward to the least.