Just what I needed - a global microsoft issue happening the day after we lost a datacenter. It does seem like I jumped the gun on this one.
I should have read mailop before making the assumption! Would still love a good MS contact, though :) - Tom > On Sep 4, 2026, at 03:41, Thomas Johnson via mailop <[email protected]> wrote: > > Cogent had two fiber cuts in Southern California yesterday. It greatly > affected our San Diego datacenter, causing all our traffic to flow through > our LAX datacenter. > > This increase in rate has caused Microsoft/Outlook servers to defer all mail > flow (even to our customers who are o365 users): > > > ❯ 2026-09-04T10:28:53+00:00 003.mia postfix-relaycust/smtp[888736]: > 4hbt2K63Nxxxxx: to=<xxxx>, > relay=xxxx-com.mail.protection.outlook.com[52.101.10.16]:25, delay=77, > delays=70/0.13/5.8/0.68, dsn=4.7.500, > status=deferred (host xxx-com.mail.protection.outlook.com[52.101.10.16] > said: 451 4.7.500 Server busy. Please try > again later from [199.89.3.6]. (S77714) > [BN2PEPF000055E1.namprd21.prod.outlook.com 2026-09-04T10:28:53.346Z > 08DF0900FB158D96] (in reply to end of DATA command)) > > > Our San Diego center is back, but the flood of mail returning to it has > caused the same issue. > > We're an email filtering service, not a bulk mailer of any type. We do > selective outbound for regular business customers (not bulk, not > transactional) - we just really need to relay inbound email to our customers > and for their normal business outbound mail to get out. > > I've submitted a request via SNDS, but I don't know if a human will see it > and intervene, and this is urgent for our customers. > > Can anyone put me in touch with a Microsoft contact who could possibly > intervene? > > Thanks- > > Tom > _______________________________________________ > mailop mailing list > [email protected] > https://list.mailop.org/listinfo/mailop _______________________________________________ mailop mailing list [email protected] https://list.mailop.org/listinfo/mailop
