Re: Hot do I stop becoming a spam relay.

WBrowne1b.org wrote:
> mimedefang-bounceslists.roaringpenguin.com wrote on
03/11/2007 10:35:43 
> AM:
> 
>> First of all my sendmail does not allow relaying,
but I am now getting a 
> 
>> lot of e-mail where email is sent to an unknown
local user and then 
>> there is a BCC to some other location:
>> for example:
>>     From: spammerdomain.com
>>     TO:    XXXourlocal.domain.com
>>     Bcc:   someoneexternal.com
> 
> What are you currently doing with those external
addresses?
>  
>> I guess the letter of the of the law I should
deliver the e-mail, to the 
> 
>> external address, since typo 's do happen, but
there must be away round 
>> it. May be I could not deliver Bcc if the to
address is invalid?
> 
> No.  You are perfectly free to respond with 550 unknown
user to the "RCPT 
> TO: someoneexternal.com" command.  It is up to
the sending SMTP host to 
> deliver the message to the right server for the
recipient. The exception 
> would be for user where your server is the designated
relay for their MUA. 
>  Access to that should be restricted by requiring
authentication, or 
> restricting it to internal IP addresses.

Yes, the 5xx rejection should be happening already if the
message comes 
from a network not specifically marked as RELY in your
access file. 
Sendmail should only attempt to deliver to your own
addresses from other 
sources.  Also note that the header contents aren't used by
sendmail 
unless the message is passed on the command line with the -t
option. 
Otherwise only the envelope addresses are used and they
don't have to 
correspond with the visible headers.

-- 
   Les Mikesell
    lesfuturesource.com
_______________________________________________
NOTE: If there is a disclaimer or other legal boilerplate in
the above
message, it is NULL AND VOID.  You may ignore it.

Visit http://www.mimedefang.org and http://www.roaringpengu
in.com
MIMEDefang mailing list MIMEDefanglists.roaringpenguin.com
http://lists.roaringpenguin.com/mailman/listinfo/mime
defang