Hi Peter On Wed, Jul 29, 2020 at 02:46:55PM +1200, Peter wrote: > On 29/07/20 8:19 am, Jaroslaw Rafa wrote: > > Could anybody explain *why* using this record by Postfix is needed at all? > > As far as I understand, SRV records are meant to be use by mail *clients*, > > to > > simplify MUA configuration by the end user (no need to type in hostnames of > > IMAP and SMTP servers, etc.) > The discussion is for smtp, which *is* a mail client.
Nope, Postfix is not a MUA. Any the whole submission stuff is for MUA with specific requirements. > > I see no big problem in manual configuration of these parameters, because > > you usually do it once. You don't re-configure Postfix every day to use a > > different submission server each time. Or I don't understand something. > > What is the actual usage scenario you're thinking about preparing this > > patch? What actual problem is it trying to solve? > The usage scenario is for relayhosts that use an SRV record to specify an > alternate port or hostname for the server. It means that if the SRV record > changes then you won't have to reconfigure Postfix each time manually. Why would the SRV record suddenly change? RFC 6186 section 4[1] allows the MUA to store the target information and not look at the SRV record ever again for subsequent connections. This somehow negates the possibility of sudden changes to those records. However, please describe how you would implement the requirements of RFC 6125 section 6[2]? You can't use SRV records without support for useful server authentication. Bastian [1]: https://tools.ietf.org/html/rfc6186#section-4 [2]: https://tools.ietf.org/html/rfc6125#section-6 -- What kind of love is that? Not to be loved; never to have shown love. -- Commissioner Nancy Hedford, "Metamorphosis", stardate 3219.8
