Just spent my Saturday on the phone with verizon. Ended with them wanting to send me a new router. All I can say is thank you to all those that think about and go to google. Changing the security setting to SSL, and port (changed automatically) on my phone and tablet was all it took. Thank you. Thank you.
I want to add my thanks. My husband has had this problem for months on his Galaxy 5. Our mobile phones are from AT&T and they said it was a Verizon problem, since that is our Internet service. Verizon said it could not be their problem because he is able to get on the Internet from his phone, and therefore it must be CompuService, his email server. CompuServe is so old that AOL, which now owns it, is not supporting it anymore without a charge (he refuses to switch to Verizon, which I use, or Gmail). Finally I found this forum through Google, whcih said to change the SSL setting which automatically changed the port, and it works. We are both very grateful to those who gave this advice.