TLS/SMTP error "couldn't convert socket to TLS"

[websurfer77]

Hello, I am running into an issue when trying to enable TLS for outbound SMTP "voicemail to email".

The setup is as follows. ISR 4431/K9 v16.12.4 running CUEv v10.2.0

Voicemail to email works fine until I enable StartTLS for SMTP via the CUE GUI. Our SMTP relay server resides in our WAN and can communicate with the CUE. I imported the certificate that I'm using on the SMTP relay server as well as the root CA certificate that was used to sign it. Still getting the same error "couldn't convert socket to TLS"

Does anyone have a configuration guide or any experience with this error message. Any help is appreciated. Thanks!

[ptripat2]

Please check if the below article helps:
https://cisco.service-now.com/helpzone?id=kb_article&sysparm_article=KB0068237

[Roger Kallberg]

I think you linked to an internal Cisco KB in your ServiceNow instance.

[websurfer77]

Hello again, can you share a link to the article that doesn't require login?

[ptripat2]

Not sure why you are asked to login, I checked with few other and it worked fine for them. Same for me. You can reach out to me 1:1 and I can share the content with you. 

[Roger Kallberg]

The link you've used and asked others employed by Cisco to verify is by the look of it an internal link.

[websurfer77]

The article link you posted is asking for login credentials. Does anyone have valid information about the error message and SMTP issue I posted above?