Comment by TheDong
20 hours ago
The 3 most common ISPs in the US are Comcast, Spectrum, and AT&T
Comcast blocks port 25: https://www.xfinity.com/support/articles/email-port-25-no-lo...
AT&T says "port 25 may be blocked from customers with dynamically-assigned Internet Protocol addresses", which is the majority of customers https://about.att.com/sites/broadband/network
What ISP are you using that isn't blocking port 25, and have you never had the misfortune of being stuck with comcast or AT&T as your only option?
Well I am not in the USA for a start but if it is blocked it must be only inbound otherwise it would break everybody.
> if it is blocked it must be only inbound
Yep, at least in France it's like this for ISPs doing this IIRC.