November 9th, 2002


Sendmail: 1, Postfix: 0. (Exim: -5.)

We've been doing some testing to see which mailer performs better as a mass-mailer, since we typically send over half a million emails to our members every day, things like reminders that they've gotten new notes (sort of like email), that they've gotten new dating matches, etc. (It's all legitimate site-news stuff and opt-out-able, if you're wondering, and with nearly 10 million users, half a million a day isn't that much.)

So here's the interesting thing we're finding. I predicted it, but everyone else was rooting for postfix.

Well, so far, the sendmail server is able to send at least 25% more (and closer to 50% more) emails in the same time period as the postfix server - and either one blows the exim servers out of the water. (We've been running exim for a while, and I finally got sick of it and decided to move on to a better mailer.)

Here are some samples, taken over the same time period:
Collapse )