My question is obvious from my title. 😀 A friend of mine had his email hacked and a second or third party is using it to spam everyone on his email list. Well I'm one of them and I contacted him to let him know. Know I don't want to block his email address just the party using it. I have to text him to send him messages because if I try to send it to his email he won't receive it. Thanks in advance , Steve 😀
Emails come through email servers, not individual IP's. Yes, individual IP's are listed in the essage header, but there's not a good way for an individual using Outlook or Thunderbird or an email client program to block based on header information.
If it says that it's from "[email protected]", that's all the rules built into an email client will understand.