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Event icon · error

This Error Event is part of Send Email Events.

Event ID · 50461

"Command RCPT failed"


The error indicates that the SMTP server has not accepted the recipient's email address.


The Command RCPT failed error indicates that the SMTP server has not accepted the email recipient's address. Some possible causes are that:

  • The email address is not in valid format.
  • The SMTP server is limiting the scope of allowed recipients.
  • Provided FROM address is not allowed.
  • Most likely, the user authentication is required.

Event examples

See some examples of the Command RCPT failed Event messages:

  • Couldn't send message, Server Response: 550 Relaying is prohibited.
  • 550 5.7.1 Unable to relay.
  • 550 Relaying denied.
  • 554 Relay access denied.
  • 554 5.2.252 STOREDRV.Submission.Exception:SendAsDeniedException.MapiExceptionSendAsDenied; Failed to process message due to a permanent exception with message Cannot submit message … [Hostname=EC9R981NB1000.USRP198.PROD.OUTLOOK.COM] 250 2.1.0


If the error returns a message similar to those above, it means that authentication with the SMTP server is required and thus has to be configured properly. Go to the Email tab of Automation Workshop Options (accessible from the Tools menu) and make sure that a Username, Password and Authentication method are correctly specified.

If unsure about SMTP server parameters or would like to use Gmail as SMTP, read more on SMTP server configuration.


Common causes of the SMTP error:

  • FROM address not allowed (you must use the same address as for authentication).
  • TO address not permitted.
  • Authentication required to send outside your organization.
  • SSL or TLS encrypted connection required to send emails.

More relaying debugging…

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