resolving email addresses {solved}

[Derek Winkler]

I'd call this more of a workaround rather than a solve.

You should still find out why your host can't resolve the from and remove
accept_unresolvable_domains it actually blocks some spam and why would you
accept emails that have no possiblity of being replied to.

> -----Original Message-----
> From: MailScanner mailing list [mailto:MAILSCANNER at JISCMAIL.AC.UK]On
> Behalf Of James D. Parra
> Sent: Tuesday, March 23, 2004 4:16 PM
> To: MAILSCANNER at JISCMAIL.AC.UK
> Subject: Re: resolving email addresses {solved}
>
>
> Hello,
>
> Adding 'accept_unresolvable_domains' fixed this problem. Thank you.
>
> Wish there was a way to have a reverse DNS lookup for
> Spammers who spoof the
> domain name.
>
> Thanks again.
>
> James
>
> -----Original Message-----
> From: Derek Winkler [mailto:dwinkler at ALGORITHMICS.COM]
> Sent: Tuesday, March 23, 2004 12:08 PM
> To: MAILSCANNER at JISCMAIL.AC.UK
> Subject: Re: resolving email addresses
>
>
> This is what I'm thinking of, you're not using this...
>
> accept_unresolvable_domains:
>
> Normally, MAIL FROM: commands in the SMTP session will be
> refused if the
> host part of the argument to MAIL FROM: cannot be located in
> the host name
> service (e.g., an A or MX record in DNS). If you are inside a
> firewall that
> has only a limited view of the Internet host name space, this
> could cause
> problems. In this case you probably want to use this feature
> to accept all
> domains on input, even if they are unresolvable.
>
> Use nslookup...
>
> # nslookup
> Default Server:  localhost
> Address:  127.0.0.1
>
> > set type=MX
> > realdomain.com
> Server:  localhost
> Address:  127.0.0.1
>
> Non-authoritative answer:
> realdomain.com  preference = 10, mail exchanger = mail.realdomain.com
>
> Authoritative answers can be found from:
> mail.realdomain.com     internet address = 192.216.19.101
> >
>
> Make sure you do it from the server.
>
> > -----Original Message-----
> > From: MailScanner mailing list [mailto:MAILSCANNER at JISCMAIL.AC.UK]On
> > Behalf Of James D. Parra
> > Sent: Tuesday, March 23, 2004 2:56 PM
> > To: MAILSCANNER at JISCMAIL.AC.UK
> > Subject: Re: resolving email addresses
> >
> >
> > Thanks Derek,
> >
> > How would I have the server find the MX records?
> >
> >
> > This is the forth MailScanner I built and previous three
> > didn't have that
> > error. Interesting though. I do see the Feature setting, I
> > think. Is this
> > it?
> > FEATURE(`relay_based_on_MX')dnl
> >
> > Thanks again for your help.
> >
> > James
> >
> >
> > -----Original Message-----
> > From: Derek Winkler [mailto:dwinkler at ALGORITHMICS.COM]
> > Sent: Tuesday, March 23, 2004 11:40 AM
> > To: MAILSCANNER at JISCMAIL.AC.UK
> > Subject: Re: resolving email addresses
> >
> >
> > > Hello,
> > >
> > > I tried to test a new MailScanner/Sendmail setup we have,
> > but from the
> > > outside a telnet session to the mail server will give an
> > > error of, "Domain
> > > of sender address "joesomebody at realdomain.com" doesn't
> > > resolve. However, I
> > > can ping the domain from the server.
> > >
> > > Any clues on how to fix this?
> >
> > You may have a feature of sendmail turned on which doesn't
> > accept email from
> > addresses which don't have MX records.
> >
> > Can the server find MX records for the domain?
> >
> > >
> > > Thank you in advance.
> > >
> > > James
> > >
> >
>