Today, by pure luck, I looked quickly to the mail server logs. Since the beginning of the year it has sent about 1500 emails.
“Ah, ok”, I think, and I move on.
Then I think about it. Hey, 1500 emails sent in a couple of days???
Looking the logs I immediately found the culprit:
After every post of a WordPress website it was enabled “share by email”!
A chinese bot, every minute, was going to the page and was sending the content to the same email address!
Result: a mail bombing!
I hope that my IP address reputation is not tarnished and doesn’t affect my deliverability…. 😡