AT&T is the worst of the worst. And I boycott them for countless reasons like snooping on their own customers voluntarily without a warrant. It’s really a hard-right corp. In any case, never tried them so I didn’t know they blocked egress 25.

One trick that works if truth-in-advertising laws are in force: ask the sales people before subscribing if the block port 25. They always say “no, we block nothing” (in my experience). So you subscribe and sign the contract. Then when you see they actually block 25, you have a false advertising situation and also a contract violation (if either verbal contracts are enforcable or if you can get it in writing that nothing is blocked). So you complain. In my experience, they give a gratis upgrade to an enterprise level of service that generally has a static IP and no blocks – for the price of the residential plan you signed up for.