XOAUTH2 authentication mechanism not supported

christiaanlouw

I managed to get the OAuth to work with the IMAP receiving but the SMTP complains that OAuth is not a supported mechanism.

christiaanlouw

I have even tried setting up a separate OAuth token for sending but get the same error.

KevinTheJedi

christiaanlouw

Well that’s a new one. Are you using a hosting provider? If so they may be blocking Outbound SMTP or something similar. I would reach out to them to see if they are blocking the request, do not support XOAUTH2, etc.

Cheers.

morphew

I get the same message when I try to connect Gmail (smtp.gmail.com) for both ports 465 and 587. It looks like everything is setup correctly, and I have the token provided by Google. Not sure where things went wrong here.

KevinTheJedi

morphew

Are you using a hosting provider?

Cheers.

morphew

I have osTicket installed on a VPS.

KevinTheJedi

morphew

Yea you need to reach out to your host to see why this is happening. I see other posts on various different forums stating this very issue was due to their VPS and switching hosts resolved the issue.

Cheers.

morphew

KevinTheJedi Good to know. I'll see what I can find out. Thanks!

christiaanlouw

My SMTP was not blocked because I have another email domain that uses basic auth and that works fine.

It's also not my oAuthV2 plugin because receiving vie IMAP works. (And my tokens are valid and pull through to MS365)

If I whitelist my Server IP on MS365, I can send mails from from OST via MS365 without auth, but then it gets flagged on the received side as spam.

I managed to get mine working by simply downgrading my OST to v1.17.4.

KevinTheJedi

christiaanlouw

Hey whatever you gotta do to get it working but in the long run it would be in your best interest to figure out and address the underlying issue. v1.18.1 actually includes an upgraded laminas-mail package which has various improvements and bug fixes included (v1.17.4 uses an older laminas-mail package); so by downgrading you are missing out.

Note:
After some very heavy research (even using "exact match" search operators, etc.) literally the only thing I can find on this exact error is multiple people linking to a single post on the Wordpress forum where someone explained the issue was due to their VPS provider.

Cheers.

ourtech

Hey there, I am also getting this same error now. I recently moved my osTicket from cPanel on CentOS to Almalinux. I generated new API key, but it is no long able to authenticate. I self manage cPanel on GCP and previously did not have this issue, so is it Almalinux the issue?

KevinTheJedi

ourtech

You need to contact your hosting provider. I doubt Almalinux itself is the culprit here as I mentioned in my post above the only place I've ever seen the error XOAUTH authentication mechanism not supported referenced is in regards to the hosting provider.

Cheers.

ourtech

I deleted the email accounts and added them and it's working again. Almalinux was not issue and nor was it the hosting. Just me not thinking 🙂 Thank you