smtp: protocol deviation
When sending emails (with attachments) through Thunderbird, we've been getting these error messages "an error has occurred smtp: protocol deviation". The email copy is delivered to the sent folder but the recipient doesn't actually get the message we sent. We have to keep sending the message at least 3 times before the recipient gets the message. That same error message will appear each time we try and send with the exception of the last message that actually gets through. We have called our email provider and they believe the error is with Thunderbird. How do we rectify this problem?
All Replies (1)
I would say hat if you keep rending the same thing over and over and sometimes it works that the problem is not in Thunderbird, but with the server accepting the mail or something sitting in the middle, like an anti virus scanner.
This post has good advice on obtaining a log that might shed light on the problem. http://forums.mozillazine.org/viewtopic.php?f=39&t=3073136
My guess however is someone with your provider is setting up a new spam rule, perhaps one that rejects mail from your IP address because you send to much mail, or the address is a domestic one and they have made a poor decision to not accept mail from their customers IP addresses, only their own web servers or something like that. I am seeing more and more poor decisions being made by mail administrators that assume outgoing mail only comes from web mail.