Outlook security alert RRS feed

  • Question

  • Hi

    We have an on-site Exchange 2016 server and users are currently using Outlook 2010. Everything works as expected.

    We have recently added a new leased line with new external IP Address range.

    We have an SMTP proxy firewall rule as follows 195.x.x.x (existing ip) to 10.x.x.x (email server)

    I added the new IP address to this rule 62.x.x.x ( new ip) to 10.x.x.x. (Email server)

    On our hosting portal there is an existing sub domain of mail.ourdomain.co.uk and A record of 195.x.x.x

    i added a new A record of 62.x.x.x against mail.ourdomain.co.uk.

    After a while users started to report that they are getting Security Alert - The security certificate was issued by a company you have not chosen to trust........ and The name on the security certificate is invalid or does not match the name of the site.

    When they click yes to proceed they are constantly prompted by outlook for user name and password and can’t connect to outlook.

    We use a certificate *.ourdomain.co.uk

    Can anyone help with this as I need to eventually remove the old ip details of 195.x.x.x as we will be cancelling this ISP



    Friday, September 18, 2020 8:05 PM

All replies

  • I'm interested in the answer to this issue too.
    Friday, September 18, 2020 9:07 PM