Am 14.02.2013 16:03, schrieb James Day: > Hello List, > > I'll have to start by breaking to golden rule of this list and not posting > postconf -n output as my question relates to a server over which I have no > control. > > A customer of mine is using a smart host provided by their ISP through which > all outbound mail is delivered smtp.enta.net (which is running postfix). > > This server holds a list of valid domain from which this customer is allowed > to send. A sensible precaution to prevent a compromised machine from sending > spam using spoofed sender addresses on other domains. > > The problem is that when clients mail server sends a NDR the sender address > is <> (ie NULL). The null sender address causes the message to be rejected > with: > > 554+5.7.1+<>:+Sender+address+rejected:+Access+denied > > Is there a sensible way to configure postfix to allow these messages with > null sender addresses to be relayed without opening the smart host up to > exploitation? > > Or alternatively - and this is off topic for this list - is there a way to > configure Microsoft exchange 2003 to send NDR's with a different sender > address. > > And before anyone comments, yes I know this isn't best practice as NDR's > should have null sender addresses to stop loops (bouncing bounce-backs!). > > Kind regards, > > James Day > (IT Engineer) >
Best Regards MfG Robert Schetterer -- [*] sys4 AG http://sys4.de, +49 (89) 30 90 46 64 Franziskanerstraße 15, 81669 München Sitz der Gesellschaft: München, Amtsgericht München: HRB 199263 Vorstand: Patrick Ben Koetter, Axel von der Ohe, Marc Schiffbauer Aufsichtsratsvorsitzender: Joerg Heidrich
