unsupported auth mechanism

[absolutely_free at libero.it]

Thank you!
I really appreciate your help



> Il 24/08/2020 18:37 Josef 'Jeff' Sipek <jeff.sipek at open-xchange.com> ha scritto:
> 
>  
> On Mon, Aug 24, 2020 at 17:11:04 +0200, absolutely_free at libero.it wrote:
> > Hi,
> > 
> > last friday I upgraded from dovecot-2.3.10.1_2 to dovecot-2.3.11.3 (FreeBSD).
> > 
> > Since then, I started having some issues with some customers.
> > 
> > The log I see is like:
> > 
> > pop3-login: Disconnected (tried to use unsupported auth mechanism): user=<username at domain.it>, method=USER, rip=x,y,x,z, lip=x,y,w,z, session=<e5KkR5qto8hPAL9q>
> > 
> > While, before upgrade, same user logged succesfully:
> > 
> > pop3-login: Login: user=<username at domain.it>, method=PLAIN, rip=x,y,x,z, lip=x,y,w,z, mpid=62876, session=<dMRmGWCtFtJtdcy6>
> 
> The only thing that comes to mind is the pop3 issue where an auth attempt
> after a failed auth attempt would always fail.  I'm not sure why the client
> that's having issues is failing the first attempt (unless it tries an
> unsupported mechanism first, and then tries to fall back to PLAIN).  Anyway,
> there is a fix on the master branch.
> 
> https://github.com/dovecot/core/commit/d0ea7f9f4530878a40ae0275cf0c36d3ff9111fc
> 
> You can try to patch the 2.3.11.3 code with it and see if that helps.
> 2.3.12 and 2.3.11.4 (if there is one) will have this fix.
> 
> Jeff.
> 
> -- 
> mainframe, n.:
>   An obsolete device still used by thousands of obsolete companies serving
>   billions of obsolete customers and making huge obsolete profits for their
>   obsolete shareholders. And this year's run twice as fast as last year's.