Sender ID (PRA) Not Permitted blocking messages

  • 7019832
  • 07-May-2014
  • 07-Aug-2017




Outbound mail is getting rejected by Microsoft servers. The return code is "550 5.7.1 Sender ID (PRA) Not Permitted". What does this mean and how is it resolved?


This is a response code from Exchange where the SPF test is failing. The sending domain has a SPF record and a SMTP gateway that is sending mail that is not included in the SPF record.

1) Detection
In order to determine if you are experiencing this issue, you will need to inspect an undeliverable message or check the gwvsmtp logs. In the logs, you would see the following:
550 5.7.1 Sender ID (PRA) Not Permitted
The undeliverable message would contain the following:
Transcript of session follows:
  Command:  Data...
  Response: 550 5.7.1 Sender ID (PRA) Not Permitted
2) Verification
Verify that your SPF record includes the host that is sending mail. If the host is not included in your SPF rules then the SPF record needs to be modified so it is included

Once the SPF record is updated, the problem should resolve itself. If the problem is still not resolved then please contact GWAVA support for further investigation

Additional Information

This article was originally published in the GWAVA knowledgebase as article ID 2287.