We include a hidden line in your email header that reads something like, "This is a bulk email. No need to reply with autoresponders." Most receiving servers pay attention to that and don't bother delivering out-of-office replies, but some don't, so you might still get a handful of those autoresponders.
Most ISPs should be using that "bulk" designation to give our mail specific (not special) treatment with regard to autoresponders, mail queues, etc. Outside of the big receivers, there could be a lot of variation on how your emails are treated when a recipient has set an autoresponder. The correct place to send an autoresponder is the Return-Path address, which is going to be @e2ma.net. If we receive one, we dump it into the trash immediately. However, there have been some cases over the years where the receiving server sends the autoresponder to the from address. It's relatively uncommon in comparison, but it certainly does happen.
Your next question might be, "Can that be changed?" This is a great question, yet we aren't able to customize this on a per-account basis, and since we are a bulk sender, we need to identify ourselves as such.