AT&T in the midwest US just blocked port 25 a few months ago. My nightly e-mails for system updates stopped coming in, and now I either have to shuttle them through an authenticated submission port or pump them over a VPN to my e-mail server. :-/
You can pay $50 and they will open it once again for you. I only know that after much trial and error troubleshooting why my public NTP service doesn’t work (port 123 also blocked).
Can the normal customer service do that? And is it $50 a month or a one time fee? Were you able to unlock outgoing port 25? (Fellow AT&T user here)
It’s a $50 one time fee. You need to call their “premium” service. Not sure if they do it per port or what, but I asked them to open all my ports and verified 25 is accessible (123 udp inbound still blocked for unexplained reasons).
They’re still clueless. I tried to explain that it’s being blocked by AT&T and not my router but eventually I just gave up. Their process involves a logmein session where they take control and mess with your router. Gahd it’s awful.
They also randomly added my “device” (home server) to the DMZ so all of its ports were exposed. Be very careful.
Re:Helm: Personal Email Server
by pathseeker on Wednesday October 17, 2018 @04:56PM
(#18243743)
>123 udp inbound still blocked for unexplained reasons
NTP was part of a massive DRDoS not too long ago. It's possible they pruned it somewhere much further up the network under the (not insane) assumption that most customers don't need to run their own time servers that answer public queries.
An ISP I worked for blocked port 25 in 2009, but it was easily reenabled by the customer checking a box in their online portal.
Considering how easily it is to setup authenticated SMTP and how effective it is at reducng spam for the ISP, I'm Surprised it took AT&T this long.
Assuming you control both sides, which sounds like you do, just run it on a different port in addition to 25.
SMTP is more problematic because of spam: outbound traffic on port 25 is blocked, so a true home mail server won't work without a reachable gateway mail server somewhere else. That's basically what the linked product is: they manage the protocol side of the service on your behalf, and forward all the content to your local device which connects to them via some internal protocol.