After sending, or during sending an email, the email is returned or error produced with the message "Error: 553 sorry, that domain isn't in my allowed list of rcpthosts"

This error is caused by not 'authenticating for sending' with our mail servers. What that means is that your email client did not prove to the mail server that you are really you. We require authentication so that only our customers can send emails out using our mail servers.

In our servers we have a special type of authenticating mechanism known as “POP before SMTP” authentication. In this mechanism when you first authenticate with our server using a valid POP account the SMTP connection is also authorized and it will remain authorized for a period of 15 Minutes. If you don’t send or receive any mail during this period you would need to re authenticate again. So to avoid receiving “553 sorry, that domain isn’t in my allowed list of rcpthosts” error please follow the below mentioned steps.

FOR MICROSOFT OUTLOOK 2003

Click Tools then Options

 
Select “Mail Setup” tab and click on “Send/Receive” button as highlighted.

 

 
Select the “Automatic Send/Receive” settings as below.

 

FOR OUTLOOK EXPRESS 6

Click Tools then Options

Under “Send/Receive Messages” select the option that is highlighted