Bellsouth/ AT&T mail problems
I would dare say there are more than a couple people “out there” right now that are puzzled as to WHY some of their mail is bouncing back to them as being rejected. Right now I’m talking about Bellsouth / AT&T mail users…. it appears that this week AT&T is in the process of transitioning it’s outbound mail relays to a new address block. 207.115.11.51 – 207.115.11.56 – the names of these machines are fmailhost01.isp.att.net – fmailhost06.isp.att.net …. Yesterday I noticed 4/5/6 had been moved – today 3 has been moved over and I noticed only because a test message that I RUN through a (formerly) bellsouth system bounced back and made it through…. The problem is the address space that AT&T is making use of used to be in the dial up block of their service and SEVERAL online blacklists have not been notified of the change. It is not possible for an end user to FIX this problem, AT&T technicians need to contact http://www.au.sorbs.net/ (SORBS) Among other locations to help their customers. The only thing techs in control of individual mailservers can do is whitelist the new AT&T addresses. (Well you could disable whitelisting altogether, but that would probably be a big HELLO SPAM).
It may be even murkier a situation – they may using BOTH sets of IP addresses (old and new) for the time being… here are two log entries that would seem to confirm that…
Jul 25 16:47:09 xxxxx postfix/smtpd[7812]: disconnect from fmailhost03.isp.att.net[207.115.11.53]
Jul 25 16:47:09 xxxxx postfix/smtpd[7812]: connect from fmailhost03.isp.att.net[204.127.217.103]
Strange… They may have some scheme to help work around this – because the connect from the 204. address immediately followed a DNS block of the connect from the 207 range address.