There seems to be an issue on some iPhones when setting up an email account. The SSL switch when turned off comes back on itself causing the error when checking emails of:
Cannot Connect Using SSL
SSL stays on even after turning it off
Workaround: manually indicate ports vs leaving them default.
Same problem here, but I might have a possible fix. I got SSL to stay unchecked if I also manually indicated a custom port, which I just put in one of the 3 defaults. Something about the "use default ports" option is causing it to force SSL.
Same problem. The workaround provided worked for me. The "use default ports" option does seem to trigger the bug. I consulted my email service provider's support web site and chose port 587. I hope this gets fixed since I would prefer to let the Apple email client select the port.
Source at Apple support