Equisys technical notes

Technical guidance, explanations and fixes for our products

PRB: Users do not receive faxes forwarded via Zetafax SMTP Server



ID: ZTN1931

This Zetafax technical note applies to:

  • Zetafax 2012 Platform Feature Pack and below


When an incoming fax is forwarded to a user via the Zetafax SMTP Server, the Mail Server that the Zetafax SMTP Server is comunicating to fails to send the email and returns an error about the MAIL FROM field being invalid. The following is an example of the error that a Mail Server can show in the logs. It may be different depending on the Mail Server but it should reference the MAIL FROM field:

[564:90] Mail from:< domain.com>
[564:90] 550 < domain.com@domain.com> , Sender unknown


This is due to a problem with the Zetafax SMTP Server where the MAIL FROM field is not accepted by the email server.


A hotfix is available that fixes this issue.


This has been identified by Equisys as a problem with the software versions given above.

Last updated: 15st March 2013 (WK/MW)

Keywords: Zetafax SMTP Server Gateway Mail From Field

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