No supported authentication methods

[deleted]

I'm getting a "no supported authentication methods" error when trying to setup SMTP using my on prem Exchange server. If I disable "Offer basic authentication only after starting TLS" on the receive connector it works. Do I need to configure PEAR to use StartTLS or does this mean my Exchange server isn't responding to the request to use StartTLS?

authentication failure [SMTP: No supported authentication methods (code: 250, response: mxserver.domain.local Hello [1.1.1.1] SIZE 52428800 PIPELINING DSN ENHANCEDSTATUSCODES AUTH GSSAPI NTLM 8BITMIME BINARYMIME CHUNKING)]

Edit:
osTicket 1.16.1 running on Server 2019 Datacenter, mysql 5.5.45, Exchange 2016 CU22 running on Server 2012R2.

KevinTheJedi

@[deleted]

We only support basic authentication at this time. Not too sure on the mailserver side of things but as long as it has a TLS port opened then you should use that port with authentication required enabled in osTicket. So that way it will connect to your mailserver over TLS, use basic authentication, authenticates successfully, and allows the SMTP connection.

Cheers.

[deleted]

KevinTheJedi
Testing from outside of the network with PowerShell shows that the port is open.
Test-NetConnection -ComputerName mail.domain.com -Port 587
This might be a routing issue the more I look at it. The IP in the error is actually our production email system although the mxserver.domain.local is the correct Exchange server. It's almost like the request is sent to mail.domain.com but prodmail.domain.com is returning the error.