I'm using EE 2.7.2
Sending out an email with Communication tool to an EE mailing list with about 3,000 people on it. Started sending fine in batches of 50, and then after about 2,300 sent it came up with this error:
Unable to send email at this time
Now when I go new previously sent emails it says the status is "incomplete" and gives me an option to finish sending the unsent messages, but when I click this I get the same error over and over again.
For the record, I have Postmaster setup to send all system emails through Mandrill. All other system emails have been working fine before and after this, so it's just a problem with sending to this mailing list via communication tool.
What would cause this very nondescript error to appear?
I first thought maybe there was an EE, Mandrill or server limitation on emails sent, but I've checked and I don't think that's the case.
Another suggestion I received is to check to make sure there isn't a malformed email address in there that is messing it up. But when you have over 3,000 emails it's very hard to look through them for something like that.
Any other suggestions of how to debug this?