From 5 days my IP is blacklisted in spamcop, the problem is that i don't understand why, of course we don't send any kind of spam, but in these last days we get many bounceback, each with many unknown email addresses in the header, instead of only 1 correct email address of my user (that obviously can not receive the email because of bloacklist)!
The email messages sent are notification for my website (like new registrations, email confirmation,..). I have already checked and secured all the scripts that send the emails and updated the phpmailer class to the lastest version.
I have tryed to send the unblock request to spamcop, but after a few SECONDS these IPs are re-listed!
I really don't understand if my website was hacked by a spammer or what its happening... how it possibile that a message send to my user or to me include many unknown email addresses in the header? and how i can resolve?
Please any kind of help is really appreciated!
PS: if needed i can provide IPs, email addressess and hosting provider