Outlook Client keeps pulling outdated certificate information

Question

so, i have an issue where we have multiple domains used for our imap mail server. up until tuesday, our SSL certificate didn't include one of the domains,a nd it generated the expected errors. monday, we renewed the certificate. on tuesday, we has the cert reissued from the certbot, including all used domains as SANs. however, we are still getting the error. upon viewing the certificate in outlook, it is still pulling the certificate from Monday. SSL labs confirms the certificate was reissued on Tuesday with the SANs, so my assumption, is that outlook is caching the SSL info for some reason. how to i force outlook to get the new SSL?

Answer 1

Hi, Joe

According to your description, the issue of your concern that you've got an error for the SSL certification in Outlook desktop client.

First, could you please tell us let us if any other users with the Outlook client encounter the same certificate issue?

Also, please be kindly to have a check to see if it's a validate auto-discover service as below:

Navigate to Microsoft Remote Connectivity Analyzer >  Microsoft Office Outlook Connectivity > click Outlook Connectivity

Once you have the results, please expand it for all detailed info and please share it with us in  private message with us for further troubleshooting.

Please feel free to contact us if there's an update.

Regards,

Zed