What is this error?

Our servers need to authenticate you as a legitimate user before allowing you to send email out.

The simplest way you are authenticated is when you've successfully checked your email. Successfully checking your email means you have access to the correct username and password, and are therefore a legitimate user.

The "503 valid RCPT command must precede DATA" error message is shown when our servers have not been able to authenticate you prior to your attempt to send email.

How do I fix the problem?

You have three basic options for correcting this issue.

1) Set your email software to use the SMTP Server provided by your ISP. Because you're connected to the internet through their network, they have no trouble authenticating you - and as such you should no longer experience this issue.

2) Always check your email prior to sending any. When you successfully check your email, your IP address is added to a 'relayhosts' file. You're then able to send email through the server for 30 minutes, at which point you'd need to re-authenticate. If your email automatically checks at intervals of less than 30 minutes, you should remain authenticated the whole time.

3) Configure your email software to authenticate you by ticking the "My server requires authentication" option or similar. The server will then authenticate your username and password each time you send mail.
Areon Reviewed by Areon on . "503 valid RCPT command must precede DATA" error What is this error? Our servers need to authenticate you as a legitimate user before allowing you to send email out. The simplest way you are authenticated is when you've successfully checked your email. Successfully checking your email means you have access to the correct username and password, and are therefore a legitimate user. The "503 valid RCPT command must precede DATA" error message is shown when our servers have not been able to authenticate you prior to your Rating: 5