Hi there,

Are they (the client) forwarding them to you in a way that you can review the Received headers?

I have seen this before, but the cause was not a reason for concern.  I get plenty of these delivered to my Gmail account.  It's either a spammer testing to see if my address is valid, or it's some sort of a bounce-back related to a joe job campaign, not sure which.

My recommendation would be to take a look at the full headers of the email.  rDNS the senders ip, and see if it comes up with some sort of domain name (or dial-up account).  If the recipient has never heard of the domain and it looks tell-tale suspicious, they should be able to safely ignore the messages.  (If the sender ip is consistent from message to message, you may also be able to block it).

Good luck!

Stephen


Edited by sgeorge