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-longer-suppo

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-longer-supported 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 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?