Scan to Email - SSL/TLS Verification Error

[SirJacobus]

Hello,

we are trying to set up direct scan to email feature (directly on the EWS) on one of our company printers but when we attempt to send a test email, following error always appears:

• We tried all possible combinations (mail server is 100% correct) - outcome is always the same above error
  • SMTP 25/587
  • With/without user authentication
  • SSL/TLS enabled/disabled
• Ports were enabled by our network department (also 25) and traffic checked - the printer obviously communicates with our Exchange server but it appears it can´t verify the secure connection - TLS 1.2 is enabled on both sides + all possible encryption modes.
• 
• There are no custom firewall settings that would be applied in the EWS.
• Printer is connected via cable to our company LAN and then to a terminal server which is also responsible for configuring spoolers to client devices (which has nothing to do with scanning of course, just for the big picture)
  • The printer is then accessible to around 6 people who can print without issues (also scan but only using local driver/HP app).
  • When I tried to configure the Scan to Mail on one of the client laptops (directly inside the "HP full SW solution" + driver), it doesn´t work either - pretty much the same SSL/TLS error.
• It seems the SMTP itself works somehow but it fails at verification... is there anything we might forgot about and shall try? In the EWS, Exchange...  The affected customer would like to have Scan to Email function and I think we are really close, probably just a small thing, dunno.
  • To be clear, our firewall system does not block the communication in any way, at least that has been verified.

Thank you for any ideas...

Jakub