Re: [gentoo-user] Re: [OT] Setting up correct domainname

[Mick]

On Sunday 20 September 2009, Daniel Troeder wrote:
> On Sun, 2009-09-20 at 21:38 +0100, Mick wrote:
> > On Sunday 20 September 2009, Harry Putnam wrote:
> > > Mick <michaelkintzios@×××××.com> writes:
> > > > -----The following addresses had permanent fatal errors-----
> > > > <email_account@×××.com>
> > > >   (reason: 550 5.1.0 <nagios@×××××××××××××××××.com> sender rejected :
> > > > invalid sender domain)
> > > >
> > > > -----Transcript of session follows -----
> > > >
> > > > ... while talking to smtp.ISP.com:
> > > >>>> MAIL From:<nagios@×××××××××××××××××.com> SIZE=745 AUTH=<>
> > > >
> > > > <<< 550 5.1.0 <nagios@×××××××××××××××××.com> sender rejected :
> > > > invalid sender domain
> > > > 554 5.0.0 Service unavailable
> > > > ================================================================
> > > >
> > > > Does this fail because the ISP's reverse DNS on my dynamically
> > > > allocated IP address resolves to an ISP domain instead of
> > > > myserver.mydomain.com?
> > > >
> > > > Is there something I could change in the configuration of my server
> > > > to make this work again?
> > >
> > > I think you might avoid the problem by making sendmail Impersonate your
> > > isps domain.
> > >
> > > Using some or all of these settings in sendmail.mc
> > >  MASQUERADE_AS(`yourISP.domain')dnl
> > >  MASQUERADE_DOMAIN(`youractual.domain')dnl
> > >  FEATURE(masquerade_entire_domain)dnl
> > >  FEATURE(masquerade_envelope)dnl
> >
> > Yes, that should fix the reverse DNS problem alright, but then people who
> > receive email notifications from myserver will be confused by the domain
> > that these messages are sent from.
>
> I don't know this sendmail feature, but I think sendmail should not
> modify your message, but just the envelop. So `youractual.domain' would
> still be in the "To"-header, while `yourISP.domain' is in the envelop.
> That should make your ISP happy, and no receiver will ever notice
> (except if they look at the headers), because MUAs only show the
> "To"-header :)
>
> Your ISP could still check the "To"-header - but that would be just
> plain ugly...
>
> > I could also use the ISP's domain for my IP address in the server's
> > /etc/hosts file - although it would have the same problem with regards to
> > the domain that messages are sent from.

I will give it a go - hopefully the ISP will be happy and I won't need to 
register with a mail relaying service.

Thanks for your suggestions.
-- 
Regards,
Mick