I have the same problem with Thunderbird and exim4.
Thanks for the workaround, but even unconditionally, it does not succeed.
Still EHLO + QUIT cause the synchronization error in /var/log/exim4/mainlog.
I also tried variations of these:
smtp_enforce_sync = false
acl_smtp_auth:
accept hosts = :
accept control = no_enforce_sync
I did a service restart exim4 in between tries.
Any further suggestions are welcome.
K-
On 2016-05-04 19:52, Jason L Tibbitts III wrote:
> So Thunderbird in the code that tests an user's account configuration.
> It connects and dumps "EHLO we-guess.mozilla.org" and then immediately
> sends a QUIT without reading the response, which of course violates the
> protocol and annoys exim:
>
> 2016-05-04 14:41:19 SMTP protocol synchronization error (next input sent
too soon: pipelining was not advertised): rejected "EHLO
we-guess.mozilla.org" H=epithumia.math.uh.edu [129.7.128.2] next
input="QUIT\r\n"
>
> Since https://bugzilla.mozilla.org/show_bug.cgi?id=538809 has
> been open for six years I don't expect that it will be fixed any time
> soon, so I'd like to work around it.
>
> One possibility is to just use:
>
> acl_check_helo:
> accept hosts = :
> accept control = no_enforce_sync
>
> which appears to work. But can I turn it off just for Thunderbird's
> probes? I tried the following, but it doesn't appear to work:
>
>
> I am pretty sure the syntax is correct and I know it worked exactly
> once. Is it possible that there's some race between processing the ACL
> and complaining about the protocol violation? Is there any better way
> to do this besides just turning on no_enforce_sync globally? I
> obviously can't narrow it down to any particular IP.
>
> Note: I'm currently running 4.86.2 as packaged by Fedora:
> exim-4.86.2-2.fc23.x86_64
>
> Any hints would be appreciated.
>
> - J<
>
>
