Symptoms
Let's Encrypt SSL certificate securing mail has been renewed on the server.
- Cannot Verify Server Identity
Settings cannot verify the identity of "mail.example.com". Would you like to continue anyway?
In iOS / MacOS mail client there is no "Trust" button on "Details" screen in the upper-right corner.
Cause
iOS / MacOS issue: system does not allow the user to "trust" a SSL/TLS certificate if an already existing mail account is set up with a not certificate by default.
Resolution
There are two possible solutions:
Solution 1. Recreate mail accounts devices
- Remove mail account from iOS / MacOS device.
- Re-create email account on iOS / MacOS device.
Solution 2. Manually install and allow using required SSL certificates from device settings:
- Get the certificate. The certificate can be exported from the browser to a .cer file:
Click on a section to expand
- Upload the .cer file on iOS device through email, Safari browser or File Sharing and install it by clicking/tapping on the uploaded file.
- Set up the email account.
- If more information is needed on the certificate, it can be found in: Settings > General > Profile.
