Blacklisted IP

[MsMaverick]

Hi there, I'm not sure if I'm posting this in the appropriate thread, but what does a Blacklisted IP mean?

I sent an email to a friend in the UK and the Mailer deamon said it failed because "Remote host said: 550 rejecting [email protected] IP is blacklisted [RCPT_TO]"

( [email protected] -> his email )

 

[HaltAndCatchFire]

It means that the isp has revoked access to a service from the specified address usually, where mail is concerned it has to do with spam so the ip address in question, was probably linked to spam or something, also, smtp, usually only allow mail originating from a known domain, ie you can;t send mail from your [email protected] address via the smtp from xxx.yyy.com because yyy.com only allows mail to be sent from yyy.com domain addresses.