LoginOAUTH2 with Zoho Mail returns expecting 'p', found 'x'

Question

Limilabs.Client.IMAP.ImapResponseException: [CLIENTBUG] syntax: expecting 'p', found 'x' at Limilabs.Client.IMAP.Imap.LoginOAUTH2(String user, String accessToken) at Program.Main()

Comments

Consider using application specific password, as I'm not sure Zoho supports OAuth 2.0 for IMAP.

Answer 1

It seems to me Zoho doesn't support OAuth for IMAP - CAPABILITY response doesn't list OAuth as a supported authentication method.

They suggest using Application-Specific Password:
https://www.zoho.com/mail/help/adminconsole/two-factor-authentication.html#alink5

You can use regular Imap.UseBestLogin method with application specific password.

As for the error:
This error is returned by your IMAP server. You may turning on logging:
https://www.limilabs.com/blog/logging-in-mail-dll
and ask your server administrator for help.