503 Valid RCPT command must precede DATA

cPanelLauren

Product Owner
Staff member
Nov 14, 2017
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Houston
The “Error 503: Valid RCPT command must precede DATA” happens only when sending an email. It's telling you that your SMTP (outgoing mail) connection was not properly authenticated by your email server. As noted by @cenourinha SMTP authentication needs to be enabled in the mail client.