This is somewhat off topic to the postfix list, but relevant to the community.
I have a client who sends about 600mgs/week total from their SBS server through our email relays. The relay IP has a positive reputation and isn't flagged for spam on any of the lists. Recently they had an issue in which email they sent to a set of users at ATT never made it to their inbox, but mail to yahoo users made it just fine. So, digging in the logs, we found that ATT did indeed accept the email just fine. The typical solution is to have the user check the spam/trash/search tools for the message, nada. Feb 2 13:30:28 hsfremto01 postfix/smtp[31326]: 4F3F882393: to=<x...@att.net>, relay=scc-mailrelay.att.net[204.127.208.75]:25, delay=1.1, delays=0.01/0/0.71/0.33, dsn=2.0.0, status=sent (250 ok ; id=20110202213026s0100mapi5e) I did the logical thing in that I put a trouble ticket in with ATT and got the automated response "Your IP isn't blacklisted". Calling several times, I never could get to a department that managed (or closely resembled) any type of tech department. Anyway, the question is, how does the community as a whole deal with big ISP's losing email? It seems that some companies (like ATT) seem to have less and less access to tools necessary for communicating with them on things like this. Is there any know lists of contact/support channels out there that people use for the larger ISP's?
