email invalid cause

[Michelle_Tizian]

When i pulled the list of bounces today, there were 3 records that were set email invalid to true, and the email invalid cause is 

550 Recipient Rejected: Access Denied: 199.15.215.79 blocked by prs

550 Recipient Rejected: Access Denied: 199.15.215.82 blocked by prs

What does that actually mean because I've not stumbled upon that email invalid cause until now, or maybe I just never noticed.  

[Anonymous · Accepted solution]

Hi Michelle,

550 error is cause when you have not completed the sender protocol.

example:

To protect from spammers, some email servers will be sending you an email request to click on a link or replay back to the email (email is either sent to sender’s email address or reply email address if any).
Your email will not be delivered to that recipient until you reply to the verification email and these kind of email will fall under 550 error.

Note: Not all mail servers adhere to these standards.

Hope this is help full.

[Michelle_Tizian]

Thanks Ramesh.  That's very helpful.