{"id":1363,"date":"2025-07-22T11:48:00","date_gmt":"2025-07-22T10:48:00","guid":{"rendered":"https:\/\/www.4uhosting.co.uk\/articles\/knowledgebase\/503-valid-rcpt-command-must-precede-data\/"},"modified":"2026-08-19T14:01:05","modified_gmt":"2026-08-19T13:01:05","slug":"503-valid-rcpt-command-must-precede-data","status":"publish","type":"kb_article","link":"https:\/\/www.4uhosting.co.uk\/articles\/knowledgebase\/503-valid-rcpt-command-must-precede-data\/","title":{"rendered":"503 Valid RCPT Command Must Precede DATA"},"content":{"rendered":"

This error normally appears when your email program tries to send mail without authenticating correctly.<\/p>\n

The mail server is rejecting the message because it has not confirmed that you are allowed to send through it.<\/p>\n

Fix the Error<\/h2>\n
    \n
  1. Open the account settings in your email program.<\/li>\n
  2. Find the outgoing mail server or SMTP settings.<\/li>\n
  3. Make sure SMTP authentication is enabled.<\/li>\n
  4. Use the same email address and password that you use for the mailbox.<\/li>\n
  5. Save the settings.<\/li>\n
  6. Try sending the message again.<\/li>\n<\/ol>\n

    What the Setting May Be Called<\/h2>\n

    Different email programs use different wording.<\/p>\n

    Look for an option such as:<\/p>\n

      \n
    • My outgoing server requires authentication<\/strong><\/li>\n
    • My server requires authentication<\/strong><\/li>\n
    • SMTP authentication<\/strong><\/li>\n
    • Authenticate senders<\/strong><\/li>\n
    • Use same settings as incoming mail server<\/strong><\/li>\n<\/ul>\n

      If It Still Does Not Work<\/h2>\n

      Check that the outgoing mail server, username, password, port, and encryption settings are correct.<\/p>\n

      If you are not sure what settings to use, check the email setup details in your 4UHosting customer account or open a support ticket.<\/p>\n","protected":false},"excerpt":{"rendered":"

      This error normally appears when your email program tries to send mail without authenticating correctly. The mail server is rejecting the message because it…<\/p>\n","protected":false},"author":1,"featured_media":0,"template":"","kb_category":[7],"class_list":["post-1363","kb_article","type-kb_article","status-publish","hentry","kb_category-email"],"_links":{"self":[{"href":"https:\/\/www.4uhosting.co.uk\/articles\/wp-json\/wp\/v2\/kb_article\/1363","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.4uhosting.co.uk\/articles\/wp-json\/wp\/v2\/kb_article"}],"about":[{"href":"https:\/\/www.4uhosting.co.uk\/articles\/wp-json\/wp\/v2\/types\/kb_article"}],"author":[{"embeddable":true,"href":"https:\/\/www.4uhosting.co.uk\/articles\/wp-json\/wp\/v2\/users\/1"}],"version-history":[{"count":1,"href":"https:\/\/www.4uhosting.co.uk\/articles\/wp-json\/wp\/v2\/kb_article\/1363\/revisions"}],"predecessor-version":[{"id":2588,"href":"https:\/\/www.4uhosting.co.uk\/articles\/wp-json\/wp\/v2\/kb_article\/1363\/revisions\/2588"}],"wp:attachment":[{"href":"https:\/\/www.4uhosting.co.uk\/articles\/wp-json\/wp\/v2\/media?parent=1363"}],"wp:term":[{"taxonomy":"kb_category","embeddable":true,"href":"https:\/\/www.4uhosting.co.uk\/articles\/wp-json\/wp\/v2\/kb_category?post=1363"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}