We are seeing that someone is sending a lots of spam using a mail address (from and reply-to) that belongs to us (we've being spoofed). They are all sent from the same mailserver, and the content is classic spam in a lot of different variants. We are not the recievers of these mails, but we get all the autoreply (as the reply-to is spoofed too). We mainly see autoreplys from 2 targeted domains, that obviously lacking in checking DMARC and SPF, that would have stopped the mails as the origin mail server isn't an approved sender in our spf records. The sender is quite aggressive as we have received about 38.000 mails of this kind the last 7 days. I have blacklisted the mailserver that is sending the spam, so it is solved in that perspective for now, but it is of course not good for us that someone is sending out a lot of spam in our name.
I have read the a bit here about how to report, but not sure if I can report this behavior? I don't have the original mails as they aren't targeted to me. It is not the spam itself i wish to report, but the MTA that is hammering out spam.
Any suggestions?
Thanks
Olof
