I guess that explains it. Though I don't get the part about tech support for those 3rd party servers. There is none! The yahoo website is useless for tech support. Can't get ahold or anyone on phone or email or forms. It's like that with a lot of companies nowadays. Can be very frustrating. I know they would have to hire tech, but that's part of doing business. They are cheaping out and leave their customers very frustrated.
Yahoo mail and Apple mail accounts are automatic setups, but Mail.com is a manual setup. At one time, Apple Mail made the details of the various email accounts setups visible, and IIRC Apple Mail has always required TLS/SSL to be turned on. Later when automatic setup for major email hosting sites such as Google, Yahoo, Apple, etc. were added apple chose to hide their setup parameters. Given the amount of tech support expended both by Apple and the provider's tech support organizations when user's messed up account settings, that was a genius enhancement. Unfortunately, there are so many email providers and their setup parameters change, so often it is not feasible for Apple to attempt automatic setup of any but the most popular (and troublesome?) providers.
