Said: 421 Message

"Said: 421 Message
rejected (in reply to end of DATA command)"

Alot of my mails returns with this messages, can anyone explain to me what this means, and how i can get rid of it?

 

If this is with Yahoo than have a look here: http://help.yahoo.com/l/us/yahoo/mail/original/abuse/abuse-60.html
Also make sure that your server is not blacklisted on: http://www.mxtoolbox.com/blacklists.aspx

 

Thanks for yuor reply.

It's not only doing it, when i send, to yahoo

My server is not blacklisted

 

Do you host your mail server on a dynamic IP address? Because most dynamic IP addresses are blacklisted nowadays.