New Dovecot service: SMTP Submission (RFC6409)

Timo Sirainen tss at
Fri Dec 22 18:05:15 EET 2017

On 22 Dec 2017, at 15.28, Tanstaafl <tanstaafl at> wrote:
> On 12/22/2017, 1:19:45 AM, Aki Tuomi <aki.tuomi at> wrote:
>> Tanstaafl, maybe you could explain what you think the BURL/URLAUTH
>> stuff is for, or do you have some particular use case you would be using
>> it? Client support already is not required, and yes, it might take a
>> long time before clients support it.
> Hi Aki,
> I would primarily just like to be able to disable 'Save to Sent' action
> in Thunderbird for accounts using a backend Dovecot+Postfix server that
> supports this.
> So, I guess I'm really confused about exactly what this is and how it
> will work.

I guess we can support this at some point. At least once we add Sieve support for outgoing submission mails it should be possible to use fileinto "Sent" command in them. But this is kind of a special use case which can't be automatically configured and isn't implemented by all clients. So it might work for you, but not generally for everyone.

> The reason I thought that Client support was required was this:
> On 12/12/2017, 1:39:08 PM, Stephan Bosch <stephan at> wrote:
>> However, keep in mind that for this particular feature we're just
>> providing the "chicken" as it were. The "egg", i.e. client support, is
>> still to come. Apart from Trojita (which I think is still not widely
>> used), I know of no IMAP client supporting BURL/URLAUTH for message
>> submission. I'd expect to see it first for clients that can truly
>> benefit; i.e., mobile clients such as K9.
> So, maybe this doesn't mean what I thought it meant... ?

This just means that the BURL/URLAUTH extensions aren't really used by existing mail clients currently. But now that Dovecot supports it, perhaps some clients will start implementing them. You can still use the submission server without the BURL/URLAUTH extensions of course, just means that the benefits are a bit less (mainly could make the SMTP AUTH configuration easier).

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