Am 12.12.2017 um 00:14 schrieb Stephan Bosch: > Hi, > > As some of you know, I started implementing the SMTP submission proxy a > few years ago. It acts as a front-end for any MTA, adding the necessary > functionality for an SMTP submission service, also known as a Mail > Submission Agent (MSA) (https://tools.ietf.org/html/rfc6409). The main > reason I created this, back then, was implementing the BURL capability > (https://tools.ietf.org/html/rfc4468). The main application of that > capability -- together with IMAP URLAUTH -- is avoiding a duplicate > upload of submitted e-mail messages; normally the message is both sent > through SMTP and uploaded to the "Sent" folder through IMAP. Using BURL, > the client can first upload the message to IMAP and then use BURL to > make the SMTP server fetch the message from IMAP for submission, thereby > avoiding a second upload. Apart from BURL, the submission proxy service > also adds the required AUTH support, avoiding the need to configure the > MTA for SASL authentication. More SMTP capabilities like CHUNKING and > SIZE are supported, without requiring the backend MTA supporting these > extensions. Other capabilities like DSN currently require support from > the backend/relay MTA. > > At this point, the submission proxy is still pretty basic. However, it > will provide a basis for adding all kinds of functionality in the (not > so distant) future. For the first time, it will be possible to act upon > message submission, rather than only message retrieval; e.g. plugins can > be devised that process outgoing messages somehow. Examples of the > things we could do are adding Sieve filtering support for outgoing > messages, or implicitly storing submitted messages to the Sent folder. > Once a plugin API is devised, you can create your own plugins. > > The reason I send this message now, is that this code is finally merged > into the Dovecot master repository. This means that it is part of the > upcoming 2.3 release. Now that it is merged, you can install and test it > from Github if you like. Feedback is of course appreciated. The > documentation is still pretty sparse, but there is currently not much to > configure. Just add "submission" to the protocols and configure the > relay MTA server. The configuration is currently only documented in the > example configuration in doc/example-config/conf.d/20-submission.conf. > The submission service is a login service, just like IMAP, POP3 and > ManageSieve, so clients are required to authenticate. The same > authentication configuration will also apply to submission, unless > you're doing protocol-specific things, in which case you may need to > amend your configuration for the new protocol. BURL support requires a > working IMAP URLAUTH implementation. > > I've updated the automated Xi Debian package builder to create an > additional dovecot-submissiond package. So, if you're using the Xi > packages, you only need to install that package and configure the relay MTA. > > Regards, > > Stephan. > > > > >
Hi Stephan, this is extreme cool ! Best Regards MfG Robert Schetterer -- [*] sys4 AG http://sys4.de, +49 (89) 30 90 46 64 Schleißheimer Straße 26/MG, 80333 München Sitz der Gesellschaft: München, Amtsgericht München: HRB 199263 Vorstand: Patrick Ben Koetter, Marc Schiffbauer Aufsichtsratsvorsitzender: Florian Kirstein
