Author: exim-users Date: To: Exim-users Subject: Re: [exim] Help with our postmaster@my.domain being spoofed as a
senderaddress
paul.mcilfatrick@??? schrieb: > Hi
>
> Having searched the exim mail archives and not found my problem there I
> thought of asking the experts.
>
> I am postmaster for a local company mail server (it is running Exim
> 4.63) that receives its e-mail from our company mail relay which does
> the virus checking of the e-mail as it arrives into the company.
>
> We have a lot of e-mail arriving for users that have left the company
> and so I created a reject-list file which is checked in the
> acl_smtp_rcpt acl so that these e-mails are rejected early which saves
> on downloading them and running them through Spamassassin (use sa-exim).
>
> This works fine for most of this type of spam.
>
> But lately, an increasing percentage of this spam is arriving with the
> sender spoofed to be postmaster@??? (i.e. me) and when Exim issues
> a deny because the recipient has left I then get an e-mail from the
> postmaster of our company mail relay sent to postmaster@??? to
> inform me that the e-mail to jbloggs@??? failed because of unknown
> user!
>
>
> How can I reject this type of spam without getting the e-mail from
> postmaster of our company mail relay?
Paul,
your local MTA is doing fine, but your company mail relay needs to do
recipient verification for the domains it is relaying to, instead of
accepting mail for recipients that don't exist. Otherwise you will
always get their collateral spam.
