Hi
I setup a osTicket in a local environment for testing purposes. The system will be used in an intranet at my company and wont be accessible from outside. Everything worked fine so far, but I cant connect osTicket to our Exchange server. I get the following error:
authentication failure [SMTP: STARTTLS failed (code: 220, response: 2.0.0 SMTP server ready)]

I tried with different users, email as username, name as username, server by name and by IP, different ports. Nothing works. When I change to a wrong port I get a connection refused error. Then I setup a local email server with hmailserver and managed to connect smtp and successfully sent emails with osTicket to local email adresses, but I cant send to the exchange email adresses (I guess the proxy blocks it). Anyway I want to run all email traffic via Exchange. What am I missing? Any ideas on how to troubleshoot this problem?
Everything is self hosted. AD authentication works flawlessly with the LDAP Plugin.
local PC:
OS Ticket v.1.14.1
Apache 2.4.4.1
PHP 7.3.12
MariaDB 10.4.10
running on Wampserver 3.2.0
Windows 10 pro
Server:
Windows Server 2012R2
Exchange 2016