Knowledgebase

Are you getting "503 valid RCPT command must precede DATA" in Outlook?

The Error indicates that you must authenticate before trying to send mail. The mail server requires authentication, which can be achieved using one of these methods:

General email client settings for any client:

Incoming Mail (POP3) Server - requires SSL: mail.domain.com or server's hostname or IP address. (NO authentication)
Use SSL: No
Port: 110

Outgoing Mail (SMTP) Server - requires TLS: mail.domain.com or server's hostname or IP address. (NO authentication)
Use Authentication: Yes (This is most important)
Use STARTTLS: No (unless you have the SSL installed & active)
Port: 25 or 587
Account Name: your full email address (including @domain.com)
Email Address: your email address (eg: username@domain.com)
Password: your password

Microsoft Outlook Express on Windows:

Launch Outlook Express.
Under "Tools" select "Accounts..."
Select your account name and click "Properties" to edit your account.
Click the "Servers" tab.
Check the "My Server Requires Authentication" check box and the adjacent "settings" button.
Ensure the "Use same settings as my Incoming Mail Server" radio button is enabled.
Click "OK" buttons twice, and the "close" button & you are done.

Microsoft Outlook 2002 on Windows:

Launch Outlook.
Select Tools > E-mail Accounts...
Select "View or change email accounts"
Click "More settings".
Select the "Outgoing Server" tab.
Check the "My outgoing server (SMTP) requires authentication" box. Make sure the "Use same settings as my Incoming Mail Server" radio button is selected.
Click "OK" button. Click "Next". Click "Finish"..

Microsoft Outlook 2000 on Windows:

Launch Outlook.
Under "Tools" select "services..."
Select "Internet Mail (your account name)" and click "Properties" to edit your account.
Click the "Servers" tab.
Check the "My Server Requires Authentication" check box and the adjacent "settings" button.
Make sure the "Use same settings as my Incoming Mail Server" radio button is selected.
Click "OK" buttons 3 times to close and save all the windows..

Microsoft Outlook Express on Macintosh:

Launch Outlook Express.
Under "Tools" select "Accounts..."
Select your account name and click "Edit" to edit your account.
Under the "Sending Mail" section, Click the "Click here for advanced sending options" field.
Check the "SMTP Server Requires Authentication" check box.
Make sure the "Use same settings as Incoming Mail Server" radio button is selected.
Close window. Click "OK". Close window.

Netscape 6 on Windows and Macintosh:

Launch your Netscape mail client.
Under "Edit" select "Mail and Newsgroups Account Settings..."
Click the "Mail and Newsgroups" menu item on the left.
Select the "Outgoing Server" menu option on the left.
Check the "Use name and Password" check box and enter your "User Name" (Which is your email address).
Click "OK".

Netscape 4.7x on Windows and Macintosh:

Launch your Netscape mail client.
Under "Edit" select "Preferences..."
Click the "Mail Servers" menu item on the left.
Under "Outgoing Mail Server User Name" enter your User Name (Which is your email address).
Click "OK".

Other email clients:

Launch your mail client.
Find the email account preferences window.
Find settings for SMTP (aka Outgoing) mail server.
Check the checkbox which asks if SMTP mail server requires authentication (if necessary).
Enter the same "user name" (your email address) and password as your incoming (POP) mail server, or click the "use same settings as Incoming Mail Server" radio button.
Save changes and close your preferences windows.