I was trying to set up mail for my server, to send status emails, gitlab emails, etc. I know this can be done with relays but I was interested in sending mail directly using SMTP. Apparently my ATT residential internet blocks outbound signals on that port by default, although there are several reports of people calling customer support and getting that changed.
The most recent thing I can find was someone on Reddit 3 years ago:
xnojack: Probably depends on the rep. Just got mine unblocked a week ago. I read online though its better to say you’re looking to allow SMTP outbound rather than port 25 outbound. Cause on the reps end its called something like SMTP outbound filter. (link)
I tried to call in and get this changed, the rep was very helpful but either something’s changed on their end or he was looking in the wrong place. Anyways, I was wondering if any of you have gone through this process recently and know if this is still a thing, or have any advice.
Yes, blocking port 25 outbound is incredibly common by default. Even on some server connections. It is probably better overall for exactly the reasons that you mentioned.
IMHO this is a bit overblown. Hosting inbound is fairly easy. Mail senders (probably for the worst) are very forgiving even if your TLS cert is expired you will probably get mail. Plus senders are supposed to retry for days if you have downtime.
However it is unfortunately true that due to spam sending is a huge pain because IPv4 reputation is a huge component. Sure you can get GMail to trust your domain after a month or so of sending if you have decent volume. But other providers who you may mail once a year are just going to go off of IP reputation. However email was basically designed for forwarding and you can use a service like AWS SES to forward your email from a trusted IP pretty easily. If you are low volume (like personal mail) there are tons of services that will do this for free.
Inbound spam is also a problem. Gmail’s filter is pretty good, and it responds to what you personally mark as spam. Other providers aren’t as good, and I don’t know if there’s any good self-hosted filter at all.
I don’t really stay on top of my gmail that often, but my spam folder has basically exactly the same stuff in it that my inbox has. Just a bunch of random emails from services that I signed up for an account on or bought something from and none of which I particularly care about. There’s not really much that I can tell differentiating what gets marked as spam or not either.
Its a problem but it isn’t a major problem. I am using rspamd without any sort of exotic configuration (basically just enabling things that are provided, not my own rules) and I only get a few spam messages leaking through a week. Maybe slightly worse than GMail but not considerably slow.
IMHO the only real missing thing out of the box is contacts checking. Which is a huge thing because it is great to have reliable delivery from contacts. But my false-positive ratio is so low anyways that it isn’t a big issue and things like the
known_sendersmodule mostly mitigates it.