Thanks for your response
osTicket version v1.10MySQL version 5.5.37PHP version 5.6.30
Yes, I can confirm the mailbox has IMAP enabled.
I've tried putting SSL:\\ at the beginning and I get the following error:Can't open mailbox {ssl:\\outlook.office365.com/imap/ssl/novalidate-cert}INBOX: invalid remote specification
I figured outlook.office365.com resolves to 40.101.54.2, so I've allowed access through the firewall on port 995. When I put the hostname as this IP address, osTicket thinks about it for about 60 seconds and then I get PHP error 500. The settings do not save.