Virgin Media Community

[TJH-L]

Hi Tim,

As requested:

NS Name=email.virginmedia.com
DNS Name=webmail.virginmedia.com
DNS Name=mail.virginmedia.com
DNS Name=mail2.virginmedia.com
DNS Name=mail3.virginmedia.com
DNS Name=pop.virginmedia.com
DNS Name=pop3.virginmedia.com
DNS Name=imap.virginmedia.com
DNS Name=imap4.virginmedia.com
DNS Name=smtp.virginmedia.com
DNS Name=autoconfig.virginmedia.com
DNS Name=autodiscover.virginmedia.com

[用心棒]

Those (12) entries correspond with what I see in the certificate. Further down from Subject Alternative Names appears Thumbprint, can you post its value here.

The same certificate that fails validity in Outlook is used in webmail. Are you able to sign into webmail?

[ha222]

c05e21fa19ebc1efa3677d8e5f92d75b8b3e6be1

[用心棒]

Thumbprint matches with what I see to. Can you select the Certification Path tab and post a screenshot of it here.

Were you able to sign into webmail?

[ha222]

Attached! I use Outlook and have no problem signing in once I say yes to 'Do you want to continue using this server' (ie VM whose certificate can not be verified)

[TJH-L]

Tim,

Thumbprint: db66c99f4f3cdb13fc2f26dd3a96c56f3ce5de16

[TJH-L]

Tim,

Certification...

[ravenstar68]

Well that's definitely not the correct certificate.  ALTHOUGH I did uninstall Norton and install AVG myself.  I got similar to yourself in terms of the certificate BUT in my case the connection to imap.virginmedia.com on port 993 still worked with no issues.

Whatever is going on, it's not an issue with the certificate itself..

I've seen one possible fix for this issue mentioned BUT:

1.  It wouldn't be an option on Virgin Media's system.
2.  You shouldn't need to do it anyway.

Based on the error message the client doesn't seem to be using the SAN list correctly and only authenticating using the CN (Common Name) on the certificate however this is just supposition on my part.

I've tested this server with Outlook 365, sTunnel, and OpenSSL's s_client tool and for me it's working on each.

[ha222]

So what is the way forward - how to resolve the problem of the certificate verification?

[用心棒]

Way forward…

• use an up to date email client; Microsoft ceased supporting Outlook 2007 as of 10 October 2017
• continue manually accepting the certificate

BTW: I agree with @ravenstar68 that the likely cause is incorrect processing of the Subject Alternative Name (SAN). Not sure why the issue was not occurring earlier other than maybe a recent update to Windows 10.