Why the mail error for domains I don't host?

[Randy Adamczyk]

hi,

On Sat, February 26, 2005 6:05 pm, Blake Swensen said:
> I am configured that way. The errors I reported were in the syslog.  Are
> you suggesting that I remove the localhost entry from sendmail.cw?

no, i guess you use relay_based_on_MX, right? i usually recommend not
using that. i don't know your setup and how many domains you are hosting,
but if you configure sendmail to accept mail sent to the domains you are
hosting instead of relying on MX records that _others_ are in control of,
you won't be vulnerable to this sort of thing anymore.

if this solution isn't feasible for you, then you could at least reject
all mail from domains whose MX points to localhost. google around for
"sendmail mx 127.0.0.1 reject" or something and you should find a
solution.

hope this helps,
randy