How to update the security certificate for the email server?

Hi, I have an ISPConfig email server and I download my mail to Outlook.
After some time, Outlook started to report to me:
The server you are connected to uses a security certificate that cannot be verified. The requested certificate is out of date.
How to update this certificate?
Thanks for your help
Martin

 

Follow these instructions: https://forum.howtoforge.com/threads/lets-encrypt-error-faq.74179/
There is also https://forum.howtoforge.com/threads/please-read-before-posting.58408/
You can force creation of new certificate with

Code:

ispconfig_update.sh --force

and allow creating new certificate when it asks. If this fails, see the Let's Encrypt Error FAQ -link.