IP Address is sending spam. Need spyware software for MacBook

If you are doing anything like that, your ISP will shut off your connection in a heartbeat, and wait for you to take steps to restore it.

That is always a SCAM.

A SPAM filter filters your INCOMING mail messages for SMAM messages. It doe snot have anything to do with sending out SMAM from your IP address.

AS Grant says, I suspect that you received a plishing email

There is so little chance that your computer is infected with password-stealing malware that trying to check for it would be a waste of time. If you want to check anyway, you need the services of a consultant in forensic computing. Running any kind of commercial "anti-malware" software is worse than doing nothing. All such software is useless.

In almost every case, this kind of incident has one of the following causes:

1. Account data was compromised by someone to whom you knowingly disclosed it.
2. The service provider had an internal security breach that it either doesn't know about or is trying to blame on its customers.
3. You set a weak password that someone was able to guess, or you chose weak security questions, or you used the same password for more than one account.
4. You fell for a phishing scam and the password was stolen.

Change the password to a random string of at least 10 characters, and never use that password for anything else. Any password that you can remember is too weak. If there are security questions on the account, the answers should also be random strings, and you have to make sure you don't lose them.

When someone reported to me that they had received spam "from me" it tuned out that someone had simply forged my credentials and sent it from somewhere else.

That email was NOT sent from my computer at all.