sendmail: open-relay

[Matthew Seaman]

Peter Ulrich Kruppa wrote:

> BTW. I have read somewhere, there might be problems with hostnames like
> pukruppa.net, since they would allow to relay all mails from .net ?!?

I'm trying to remember where this appears.  I remember vaguely what
you're referring to, and yes, it's a theoretical possibility if you
combine a name like that with domain name based access controls.  Aha!
Found it.  It's this item in the 'FEATURE' section of 
/usr/share/sendmail/cf/README

relay_entire_domain
                This option allows any host in your domain as defined by
                class {m} to use your server for relaying.  Notice: make
                sure that your domain is not just a top level domain,
                e.g., com.  This can happen if you give your host a name
                like example.com instead of host.example.com.

So, unless you have an entry saying FEATURE(`relay_entire_domain')
somewhere in your sendmail configuration, this will not hurt you.  

	Cheers,

	Matthew

-- 
Dr Matthew J Seaman MA, D.Phil.                   7 Priory Courtyard
                                                  Flat 3
PGP: http://www.infracaninophile.co.uk/pgpkey     Ramsgate
                                                  Kent, CT11 9PW

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