Equisys technical notes

Technical guidance, explanations and fixes for our products

ZTN2095-PRB Multipart faxes submitted using API are truncated when resent



ID: ZTN2095

This Zetafax technical note applies to:

  • Zetafax version 17.0 and earlier


Faxes which are submitted using the Zetafax API can be resent or forwarded to another fax number using the Zetafax Client.  However in some cases the forwarded fax will be truncated, with one or more of the pages at the end of the fax being omitted from the second fax message.

This occurs when all of the following conditions are true:

·         The original message was submitted using the Zetafax API

·         The message which was submitted comprised two or more separate message files

·         The first message file was not either TIFF-FAX or ASCII text format

·         The resend action was carried out using the Zetafax Client application


You can avoid this issue by changing the application which submits the faxes so that the first message file is in one of Zetafax “native” file formats – either TIFF-FAX format or ASCII text.

There are several ways of achieving that, including the following:

Option 1 – add an extra %%[TEXT] section to SUBMIT file

If the message is being submitted using a SUBMIT format file, then the file will typically have the following format:

To: Sam Smith
Fax: 222 333 4444



To add an empty ASCII text file as the first message file, add an extra %%[TEXT] section before the first file as follows:

To: Sam Smith
Fax: 222 333 4444




Option 2 – change the file format to TIFF-FAX

If you can control the format of the files which are being submitted, then you can avoid this issue by supplying the files in TIFF-FAX format rather than an alternative graphics format.

TIFF-FAX is an industry standard format, and is well supported by graphics converters and other graphics applications.  It includes the following settings:

·         Monochrome 1 bit per pixel

·         Resolution 204x196, 204x98, 200x200 or 200x100 dots per inch

·         Image width 1728 pixels

·         Compression CCITT3 Modified Huffman (1D)

Supplying the message file in this format is also likely to improve the image quality of the sent fax as Zetafax will not have to reconvert the file to change image resolution and other settings.


This issue is caused by an error in the processing of multi-part message files by the Zetafax Client when forwarding a message, and will be corrected in a future release.

Last updated: 24thMarch 2016 (GW/NT) 

Keywords: API, Automation, Toolkit


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