OpenEMM Technical Support Forum

I can see from my maillog that the main email providers, Yahoo, Gmail, AOL, etc, will put my IP address on a deferred list if I send them too many emails too fast. They do eventually lift the deferred status after some time passes. So although OpenEMM says that the emails were sent, they are really just out of the OpenEMM queue. The emails may be in the sendmail queue stuck on a deferred list where they get re-tried by sendmail. These deferred emails show up on the OpenEMM bounce stats as soft bounces.

So anyway, I'm trying to figure out at what speed I can send out emails without triggering this deferred problem from the receiving server. Of course this is a obscure question because the email addresses are sent in an arbitrary order. We don't know if the next group of mail to send is all from the same domain name, or if they are all different domains.

So far what I do know is that sending out about 40,000 emails at 10,000 emails an hour is not a good idea, it resulted in a lot of deferred emails. Right now I've got another 40,000 emails going out at 15 emails per minute, and I haven't seen any problems with deferred emails.

My question is what speed to you guys send out your emails to avoid any problems from the receiving servers?

For lists < 100,000 recipients we usually work with a blocksize of 500 - 1,000 emails and 5 min. break between the blocks. This results in 6K - 12K emails per hour.