Outlook POP3 cant connect to exchange 2007

[dajohnso]

I have an exchange server 2007 thats been working for years. All of a sudden ALL users are getting an error message in outlook that:

"log onto incoming mail server (POP3): Your server does not support the connection encryption type you have specified. Try changing the encryption method. Contact your mail server administrator or internet service provider (ISP) for additional assistance".

Outlook is configured for SSL and port 995 on the "incoming server POP3"

I have made no changes to the server or client configurations (except maybe windows updates). Its happening to all clients so I assume this is a server issue. I disabled anti-virus on the mail server and client for testing and I verified that server configuration->client access->"MAILSVR"->POP3 properties the binding tab has the following settings:

TLS or Unencrypted Connections

Specify the local IP address and ports that you want to use for either TLS connection or unencrypted connection

(all available IPv4 address) 110​

secure socket layer (SSL) Connections

Specify the local IP address and ports that you want to use for a SSL connection

(all available IPv4 address) 995​

No changes to the firewall (verified port 995 is open to mail server). OWA works fine so I know its not username/password issue.

I believe this happened once before (Jan 2018) and I fixed it but I don't remember what I did (it was a google search) and I don't seem to be finding a solution this time.
My OUTLOOK error logging has (mail server URL replaced with XXXXX):

2019.06.23 01:35:36 POP3 (mail.XXXXXXXX.com): Port: 995, Secure: SSL, SPA: no
2019.06.23 01:35:36 POP3 (mail.XXXXXXXX.com): Finding host
2019.06.23 01:35:36 POP3 (mail.XXXXXXXX.com): Securing connection
2019.06.23 01:35:36 POP3 (mail.XXXXXXXX.com): Disconnected from host

 

[DrB0b]

Is you Cert expired? I think it should give you a cert expired error instead but worth checking.
When is the last WU that installed?

Learning - A never ending quest for knowledge usually attained by being thrown in a situation and told to fix it NOW.

 

[AdrianGates]

Roll back your last update on exchange server 2007

Adrian G,
Hosted QuickBooks Expert

 

[BN75]

Exchange 2007 is End of Life in 2017 - no support or patches for over 2 years ( unless you have contract extension ).

Possibly a TLS version mismatch?
Like the server only supports TLS v1.0 but the client only supports / is requesting TSL v1.2?