What is 554 Message?

[Bert]

I am having email return becasue of this "554 message". It says "554 Message
contains known spam source in Received: header>"

Can anyone help? What can I do here?

 

[Brian Tillman]

I am having email return becasue of this "554 message". It says "554
Message contains known spam source in Received: header>"

Can anyone help? What can I do here?

That's a message from your recipient's server saying that it found a
"received" header in your message that it didn't like. In other words, your
recipient's server is blocking your mail.