How to Resolve “Error 503 Valid RCPT Command Must Precede DATA”

Last Updated on Tuesday, 1 February 2011 03:52 Written by Naveed Ashraf Monday, 31 January 2011 02:06

Related to: Email sending/SMTP problem on the client side

“Sending’ reported error (0x800CCC65) : ‘Your outgoing (SMTP) e-mail server has reported an internal error. If you continue to receive this message, contact your server administrator or Internet service provider (ISP). The server responded: 503 Valid RCPT command must precede DATA’”

The most common reason for this issue is that your mail client fails to authenticate the server. Generally, this is caused when the email client’s (for example MS Outlook) SMTP authentication is not switched on.

This error can be resolved using the following: