Network Solutions SSL Certificate Reviews

I have been a user of their web forwarding and e-mail services for many years. in the past, they seemed OK. At present they are forcing their e-mail users to upgrade to a different website using SSL and TLS, which might be fine, but their certificate cannot be verified! What slimy jerks! They do not appear to have tested to see if their updated process works with even common Android e-mail clients, including Microsoft Outlook for Android - it fails without providing a clear diagnostic, and their support people are clueless about what is going on. How can a firm that sells certificates not know this? How could they force their users to migrate without testing the most basic functionality for some of the most common Android apps? I am disgusted, and will cancel my various services as quickly as I can find replacements.