In this post, let’s have a look at the error code “421 RP-003” that you get as bounce back when you are trying to send a email via Microsoft’s Outlook.com.
Every Mail Servers that uses SMTP protocol to send emails have a list of errors that is usually displayed to the user when there is an email bounceback. Here’s we look at a specific error code that we receive and what it means for the user when using outlook ot Hotmail.
The mail server IP connecting to Outlook.com server has exceeded the connection limit allowed. Reason for limitation is related to IP/domain reputation. If you are not an email/network admin please contact your Email/Internet Service Provider for help.