Invalid server certificate error

When your computer or mobile device attempts to access your mailbox with a secure connection, a digital certificate (commonly referred to as an SSL certificate) is used to encrypt the connection. By default, the Anno server uses the certificate attached to the server hostname (i.e. the main domain for the server), which is not the same as your own domain. This is perfectly valid, but some email clients do not handle this correctly and throw errors. In particular, we quite often encounter iOS devices being tempramental about the issue.

The solution to the problem is simle: install a digital certificate for your domain. A free option and completely sufficient solution is to use a Let's Encrypt certificate — it costs absolutely nothing and is easy to install:

  • Log in to your cPanel at (replace with your actual domain)
  • Go to the Let's Encrypt SSL page and follow to the prompts to install a certificate for your domain(s).

For more information about our Let's Encrypt service, please see the following blog post:

Note: A Let's Encrypt certificate has a relatively short lifespan of three months. We have configured cPanel to automatically renew your certificate a couple of weeks before expiry.

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