
Setting up the same account (with completely identical settings and credentials, all verified to be correct in the host’s admin panel) works fine on my own and my dad’s iPhone and iPad, even accessing the Internet on the same network as the devices where it doesn’t work. Saying yes to its suggestion of trying without SSL doesn’t help still can’t connect. I’ve tried completely removing the account, restarting the device and adding it as a new account it then says “Cannot connect to server using SSL” when setting up the account. The error is never “Incorrect username or password”, always that the server does not respond. All settings and credentials (username/password) have been confirmed in the host’s admin panel and are correct. Verify that you have entered the correct account info in Mail settings”, and I haven’t been able to get it to work since. The e-mail account had been working on her iPhone and iPad for years – but when I changed the password in the website admin panel and then updated it in Settings → Accounts on the two iDevices, they both said “The mail server is not responding. Note: The problems described here also apply to the outgoing SMTP server, which is on the same domain as the IMAP server.

The mail server is a simple, bog-standard IMAP server run by the host – no hosted Gmail or anything like that, just plain IMAP. One of those accounts is an IMAP e-mail account associated with their website. My stepmum received a notification that an attempt by someone to log in to her Google account (with the right password) had been blocked, so I started changing passwords for the accounts where variations of that password were used.

I’m having a bit of a brain-scratcher with my parents’ phones and iPads.
