|reply to HELLFIRE |
Re: [Servers] strange b2b email behavior
You are correct, we have had no other connectivity issues, that same email server sends messages to many different servers.
Today we spent considerable time with the receiving server in question. They went through turning off all spam, all firewall, and we still couldn't send anything larger than 250k. Smaller files went fine, but anything larger (which could be a regular 1-5mb pdf) failed.
What we finally found is that my smtp server and their receiving host (Smartermail) were not negotiating properly. I changed smtp smarthost on my end, and everything flowed into their server. You were right on in one of your statements that it really looks like an application issue.
They are looking into possible bugs in that particular email server software and normal smtp gateway.
Pretty bizarre, but at least we have pinpointed the issue.
Thanks again, close this ugly case up!