Hi,
> On 17 juin 2020, at 15:08, Matus UHLAR - fantomas <uh...@fantomas.sk> wrote: > > On 17.06.20 14:37, Patrick Proniewski wrote: >> I have at work a Postfix infrastructure that sits between Internet and our >> Exchange servers. Postfix is used for MX and SMTP roles, ensure filtering >> with Amavisd/Clamav/etc. >> For some time now I notice that some messages, either originating from >> Internet or from internal servers are bounced when they arrive on the last >> hop: Exchange. > > AFAIK this happens with messages that contain 8-bit headers. > >> Jun 17 12:34:20 postfix-mailgw/smtp[77347]: 57F56EB256: >> to=<login@exchg.domain>, orig_to=<userpart@domain>, >> relay=Exchange-VIP[Exchange-VIP]:25, delay=0.01, delays=0.01/0/0/0, >> dsn=5.6.7, status=bounced (SMTPUTF8 is required, but was not offered by >> host Exchange-VIP[Exchange-VIP]) > > I have this problem too a few times a day. It becomes quite frequent these days unfortunately, and we've experienced it with internal emails too which is more problematic. Currently I count about 150 to 180 bounces per week. > >> I'm suspecting something fishy with Amavisd, but I can totally rule out a >> mis-setting on my Postfix servers. > > amavisd is outta here. > > apparently it _could_ reformat 8-bit headers but I'm not entirely sure if it > should and if it supports that. On our MX servers I've setup a partial debug (log debug only for some particular recipient) in order to gather stats like DNS timing during analysis, etc. It allowed me to see this kind of things: Jun 11 08:13:23 amavis[82395]: (82395-16) orcpt_encode rfc822, foo@domain, smtputf8 Jun 11 08:13:23 amavis[82395]: (82395-16) orcpt_encode rfc822, bar@domain, smtputf8 I don't know if it's meaningful or not (those particular messages won't bounce), and it might just as well be a notice because the current Postfix involved supports smtputf8. regards, patpro
