Hey guys, was wondering if you could help me understand how to resolve this. I've never been very knowledgeable about sendmail stuff.

So my web server runs a fairly recent and pretty vanilla OpenBSD. I host a few web sites on it and use it for a local DNS server.

Some spammers somewhere are sending their messages using my domain names as originating domains on their emails. When those emails bounce, I get a error email to root notifying me of the bounce. I think that's all there is to it, I have relaying turned off and I don't think my machine contributes in any way except for being responsible for the domain on the faked "From" field.

I get hundreds of these a day lately. I became aware of this when it filled up the disk with /var/log on it.

What is my best recourse here? Am I correct in what the cause is?

Thanks you guys,

Jim