The best replacement for qmail is sendmail.

The best alternatives to qmail are rated as following:
★★★★★  sendmail
★★★  exim
★★  postfix
★  dovecot
  iredmail
  gmail
  postfix which is better

Your alternative for qmail is not listed? Suggest!
Speaking about qmail, one probably shouldn't forget about spamassassin.

Other search terms related to qmail and their ratings are:
★★★★★ spamassassin
★★★★ squirrelmail
★★ procmail
★★ openwebmail
★ vpopmail
clamav
horde
You have in mind a companion for qmail and it is not yet here? Propose!



Google Trends

Scale is based on the average worldwide traffic of qmail in all years. Click on graph for more.
qmail
sendmail
exim