Link to home
Avatar of mmj1
mmj1Flag for United States of America

asked on

Outlook 2016 - security certificate issue when opening outlook

I have Office365 locally installed on a PC with the email account setup as IMAP.  All was working ok but now have a few issues:
1) When opening Outlook frequently (not always) getting a send/receive error - usually a reboot will correct
2) Yesterday - started getting the following message:  "Internet Security Warning" - The server you are connected to is using a security certificate that cannot be verified..... do you want to continue using this server.

I have two different email accounts setup in Outlook (one goes through Yahoo servers and the other through Total Server Solutions (previously Hands On Webhosting) - both accounts are setup as IMAP.

Any help is appreciated!  Thank you.
Avatar of Scott Kunau
Scott Kunau
Flag of United States of America image

Blurred text
View this solution by signing up for a free trial.
Members can start a 7-Day free trial and enjoy unlimited access to the platform.
See Pricing Options
Start Free Trial
Avatar of David Favor
My guess is this relates to a broken load balancer or proxy.

Better to test + know, than guess.

Provide the hostname of the IMAP server you're connecting to for testing.

If you must do this yourself, what you're looking for is if the IMAP instance has a fixed IP or an IP pool.

What you describe sounds like an IP pool, where one or more IPs have some config which is incorrectly serving your cert.
Avatar of mmj1


Thank you both for your input.  After further review, we think this issue with the "Internet Security Warning" is due to a site we are navigating to that needs to renew the SSL certificate - that is being worked on so I'll know once they renew it if that was the problem.   I am going to close this question and award you both points for your assistance.  If the cert issue is not resolved by the renewing of the cert I may need to log another question.  Thanks again.