SSL certificate warning on devices when connecting to a mail server

Email SSL certificate warning on Apple (and other) devices when connecting to a mail server

Email software and apps running on an Apple device (i.e. macOS or iOS) will require you to make an exception if the SSL certificate provided by the server doesn’t match the hostname you’re connecting through. If this SSL certificate is changed or renewed, which will happen at least once a year, another exception would need to be made.

A similar issue can also appear using various email clients on other systems such as Windows, Linux and Android.

By default, the mail server we would advise you to use would utilize your own domain name (e.g. This will allow you to connect through a mail client, but if you attempt to connect with SSL enabled this will show a warning, something like: Certificate Mismatch. The recommended method of enabling secure connections would be to connect using the mail server’s actual hostname (e.g.

Most email software and apps will allow you to either ignore the warning or provide an exception. Apple devices should let you do this the first time you connect, but when our SSL (* renews, Apple devices will show another Certificate Mismatch error similar to when you set the email account up, but won’t allow you to ignore the warning.

To set this up correctly you should change the incoming (IMAP/POP3) and outgoing (SMTP) servers to use the actual hostname of the server. If you don’t have the * type hostname please contact support with your domain name so that we can supply you with your email hostname.

Alternatively, you can just turn off ‘Use SSL’ in the settings by going to:

1. Settings
2. Passwords & Accounts
3. [Your Account]
6. Primary Server
7. Turn Off ‘Use SSL’
8. Done
9. Account
10. Advanced Settings
11. Turn Off ‘Use SSL’
12. Account
13. Done

This does however mean that your connection to the server will not be secured.

Or you can try to add another certificate exception manually via Keychain, but this isn’t something Support would be able to help with.

A final option would be to remove the email account from the device and then add it back again so that a new exception (Trust) can be created. We only recommend this option if you are using IMAP and all your existing messages are kept on the mail server. If using POP3 you would need to ensure that your email messages are fully backed up before deleting.

Also, if you ever find that this hinders you from accessing your email, you can also access your email using Webmail at (or