I like to help on this. Please let me know the GIT repo so I will clone it and will make corrections.
Basic Authentication Retirement for legacy protocols in Exchange Online
Our code for this is internal only right now. We will release a test build soon. Please stay tuned.
Cheers.
2 months later
KevinTheJedi Has there been any update on this? Our Org has made some changes and if its not supported soon I'm afraid we are going to have to drop OSTicket....
The update is we hope to have it released by the end of May. We are currently wrapping up the OAuth2.0 side of things then once complete we are connecting it to the new mail backend and doing some final testing.
Cheers.
a month later
KevinTheJedi Hate to pester again but I'm geting pressure from higher ups has a specific date been decided for the release that will have the support for Oauth2.0?
Thanks.
7 days later
KevinTheJedi Sorry to pester again the reason I ask is our organization has decided to push the requirement sooner than microsoft has. Is there a specific month the release is planned for?
Add our voice to the throng. We're very excited to get this into production, but the modern auth/Oauth2 is a hard requirement for us.
Google ends support on 30.05.2022
(so in 5 days)
Same here. Please notify us of when osTicket will support modern auth.
7 days later
Hello, any updates on this?
I cannot receive any new tickets for 2 days now!
Is there a plugin we can use in the interim for 365 and/or Google Auth?
It appears that this change: https://support.google.com/accounts/answer/6010255?hl=en&visit_id=637897775950612434-2079486393&p=less-secure-apps&rd=1#zippy=%2Cif-less-secure-app-access-is-on-for-your-account from Google impacts our ability to use osticket for email polling as of May 30, 2022
Yes, we are hoping to have v1.17-rc1 released within the next few weeks. Stay tuned!
Cheers.
next few weeks or days ?? 
Looking like next week or the week after. People don’t realize how big of a change this is. We are literally changing the basis of the software.
Cheers.
KevinTheJedi Definitely a huge change. While the push back sucks, I appreciate you being responsive on the forum and keeping us as up to date as you are able to. Will be waiting for the update and thank you for supporting this huge change!
- Edited
We really appreciate the kind words. It’s been the biggest struggle to get this working. We had to change the entire plugin architecture, create a new OAuth plugin, ditch the old PHP pear libraries, setup a new library (laminas-mail), and change the entire basis of the software (everything email). Excuse my language but PHP really fucked developers by not supporting OAuth via native imap functions, etc.
Cheers.