Forum Discussion

C_the_S

Bronze Contributor

Mar 06, 2017

Certificate Error

Couple of my users are receiving this error for outlook.office365.com in Outlook 2010. Any ideas?

Bronze Contributor

Mar 08, 2017

No, our email has been in Office365 for 2 1/2 years now.

We haven't seen the error since it first occurred so I'm going to pressume it was a temporary error on the server side.

Kamal Ibrahim

Copper Contributor

Mar 08, 2017

Up to you but would recommend to get users with older version of outlook to run this tool to get latest updates from 365. https://www.microsoft.com/en-us/download/details.aspx?id=50360

Been O365 Support Engineer, we had few customers having issues.

C_the_S
Bronze Contributor
Mar 08, 2017
Our Office 2010 is already up-to-date.
- Dongjie
  MVP
  Apr 05, 2017
  HI cary！
  Trouble to confirm whether all users have this problem。
  If it is a few users, reconfigure Outlook is resolved!
- Alan_McFarlane
  Iron Contributor
  Mar 29, 2017
  We had a DNS server (small-office router actually) apparently corrupting DNS lookups – I suspect because the record Office 365 returns is rather large, what with multiple addresses and IPv6 addresses. Outlook was presumably thus sent to an adjacent server in the Microsoft server farm. Certificate errors was the error there. It would be interesting to see what server names were allowed by the certificate.