Secure Site Documentation

System Limitations

The following list represents the most important limitations in the InterFAX system. Other limitations may apply, but will usually not have an impact on users. Please note that this list may change over time.

For any specific questions, please contact Support.

Outbound Service

  • Maximum number of pages per fax: 100 pages (more can be accommodated by special request).
  • Maximum number of email-to-fax recipients (total addresses in “To:” and “Cc:” lines): 500
  • Maximum number of recipients in a single submission (faxing via lists or submission via Web Service): 20,000
  • Maximum total filesize of fax attachments: 20MB
  • Maximum total filesize of fax attachments, where the email is electronically signed: 10MB
  • Fax images are stored and visible for: 14 days.
  • For prepaid users: Fax information is kept for 30 days after the prepaid card that was used at the time has been depleted.
  • For invoiced users: Fax information is kept for 30 days after the end of the month during which the fax was sent.
  • Maximum postpone time: 30 days.
  • No support for password-protected files.
  • No support for read-only files (which bring up a pop-up when opened)
  • Macros are disabled. Do not use macros in case they affect document output.
  • Supported attachment file types: See complete list at Supported File Types.
  • Charset ‘Windows-31J’ is currently not supported by Windows, as a result it is not supported by InterFAX. As an alternative, please use Charset ‘shift_jis’ instead. For more information, please see the article – here.
  • Maximum number of file attachments in Secure “Send Fax” and “Send Merge”: 5
  • Maximum frequency of polling for fax status: up to 6 requests per minute.

Inbound Service

  • The account manager may define up to 10 shared properties.
  • Maximum number of forwarding addresses: 25 addresses.
  • Maximum allowed time between page breaks: 600 seconds.
  • The user may download fax image/s in the following formats: PDF, TIF, PNG.
  • Users can store received messages and view them for 12 months. Extended storage period is available, please visit our Prices page for additional details.
  • Maximum frequency of polling for fax status: up to 6 requests per minute.

SOAP Web Service

  • Maximum request size of any type: 4 MB.
  • Maximum file size when using partial upload: 20 MB.
  • Maximum frequency of polling for fax status: up to 6 requests per minute.
  • Maximum number of items returned in the following methods: (for outbound faxes) FaxStatus,
  • FaxStatusEx, FaxQuery, FaxQuery2 and (for inbound faxes) GetList, GetList2: 100 items.
  • However, when querying by verb Parent in the FaxQuery and FaxQuery2 methods (that is, when retrieving transactions in a broadcast): 20,000 items.
  • Maximum chunk size when using GetImageChunk download (of inbound faxes): 4 MB.

REST Web Service

  • Maximum request size of any type: 4 MB.
  • Maximum frequency of polling for fax status: up to 6 requests per minute.
  • Maximum number of items returned in the following methods: (for outbound faxes) Faxes, Completed and (for inbound faxes) GetList: 25 items.

Online Control Panel

  • Session timeout (time of inactivity before user is logged out): 20 minutes.
  • Secure session timeout is 15 minutes; Fax Viewer session timeout is 15 minutes also, but it has its own counter.
  • Response timeout: 90 seconds.
  • Maximum file size of fax image for downloading from the site: 4 MB
  • The online control panel is supported by the following web browsers: Google Chrome, Mozilla Firefox, Internet Explorer 9 and up for Windows.

Fax Number Examples and Format – International, Long-Distance and Local

The Internet fax service from InterFAX lets you send a fax from email programs without having to install a fax modem or any fax server. Whether you are one person sending faxes from your SOHO or an organization with thousands of employees, our internet fax service saves you time and money. You can send faxes for as little as $0.07/€0.07/£0.04 per page, without any setup fees or monthly fees.

InterFAX is designed to be as similar to dialing your fax machine as possible. The principle is to specify a fax number as if you were dialing it from your standard phone. However, you may add access codes (long-distance, international), as well as country codes and area codes. In case no explicit access codes or prefixes are specified, InterFAX will automatically add them according to your user settings.

For reading convenience, a fax number may contain any characters, such as hyphens, parentheses etc. Any non-digit character is ignored, with the exception of a plus sign, which is used as a generic International Access Code.

Fax numbers that contain brackets needs to be written as quoted string, see examples below.

The safest fax number format

If you are not sure what your user settings are, simply use the following standard international access notation:


+(country code)(area code)(fax number)
for example: +1-212-9876543
or +44-208-1234567

Other international fax number examples

Example 1:

User is configured to dial from New York, NY, USA.

Faxing from US to UK:
Option 1: +44 161 999 8888
Option 2: “011 44 (161) 999 8888”
Note that a US-based user (as defined in account defaults) can dial the US-specific international access code 011.

User wishes to send a fax to another area within the United States:
Option 1: 1-408-999 8888
Option 2: “+1 (408) 999 8888”

User wishes to send a fax to another phone number IN New York:
Option 1: 222 8888
Option 2: 1-212-222 8888
Option 3: “+1 (212) 222 8888”

Example 2:

User is configured to dial from London, UK.

User wishes to send a fax to another country (USA, with country code ‘1’):
Option 1: +1 212 999 8888
Option 2: “001 (212) 999 8888”
Note that a UK-based user (as defined in account defaults) can dial the UK-specific international access code 00.

User wishes to send a fax to another area within the UK:
Option 1: 0161 999 8888
Option 2: “+44 (161) 999 8888”

User wishes to send a fax to another phone number IN London:
Option 1: 2222 8888
Option 2: 01-2222 8888
Option 3: +44 1-2222 8888

Register

Register now to try our internet fax service.

InterFAX Features and Benefits

  • Send and receive faxes without fax machine, paper or toner
  • No need to leave your computer on at all times in anticipation of a fax
  • Archive faxes digitally
  • Fax from anywhere

Supported File Types

The following table lists file types supported as attachments by the InterFAX service. See also System Limitations for unsupported file behaviors.

Note: Attempting to send a file with an extension which is not its native extension, as defined below, will result in a rendering error.

Document Extension File Type MIME type
DOC, DOCX Created by Microsoft Word 97, 2000, XP, 2003, 2007, 2010, 2013, 2016 & 365; Google Docs; Zoho Docs. application/msword, application/vnd.openxmlformats-officedocument.wordprocessingml.document
DOT Created by Microsoft Word 97, 2000, XP, 2003, 2007, 2010, 2013, 2016 & 365. application/msword
XML Currently supported XML types: Microsoft Word 2003 XML application/xml
PDF Adobe Acrobat (Version 9) application/pdf
TIF Group 3 TIFF, may be in standard or fine resolution **** image/tif
TXT ASCII Plain Text text/plain
XLS, XLSX Microsoft Excel 97, 2000, XP, 2003, 2007, 2010, 2013, 2016 & 365; Google Docs; Zoho Docs
Note: Only active worksheets will be faxed
application/vnd.ms-excel
HTM/HTML*** HTML files Note that HTML is opened and converted to faxes using Internet Explorer v6 (as of June 2013:) v10. text/html
MHT*** MHT web archive files; HTML with embedded images
Note that HTML is opened and converted to faxes using Internet Explorer v6 (as of June 2013:) v10.
message/rfc822
URL Windows URL files
Notes: 1.) The contents of the linked page will be faxed; 2.) HTML is opened and converted to faxes using Internet Explorer v6 (as of June 2013:) v10..
application/internet-shortcut
PPT, PPTX Microsoft PowerPoint 97, 2000, XP, 2003, 2007, 2010, 2013, 2016 & 365; Google Docs; Zoho Docs application/vnd.ms-powerpoint
GIF Non-animated GIF files * image/gif
PNG PNG files image/png
JPG/JPEG JPEG files * image/jpg
PS PostScript application/postscript
EPS Encapsulated PostScript application/eps
RTF Rich Text Format application/rtf
BMP Windows Bitmap * image/bmp
PCX PC Paintbrush Bitmap ** application/pcx
SNP Microsoft Access Snapshot (Version 10 on Windows 2000) application/snapshot
ZIP Any of the above file types may be compressed as a zip file. Multiple files within a single zip file are allowed. application/zip

** For best results use only monochrome (1-bit color, not grayscale) with the following image sizes

*** HTML documents are rendered using MS Internet Explorer, with page margins set to 10.16mm (left, right, top, and bottom)

****Image Sizes

Standard Resolution Fine Resolution
Width Height Width Height
A4 1,728 1,169 1,728 2,338
Letter 1,728 1,100 1,728 2,200
Legal 1,728 1,400 1,728 2,800
B4 2,048 1,357 2,048 2,714

InterFAX Status Codes

Color code legend

Color & Meaning Comment
In process The fax is in the process of being prepared, sent, or resent. This is a temporary status; it may change. Query again later to determine whether the fax has completed.
Success The fax has been sent successfully. This is a permanent status; it will not change .
Failure The fax has failed, even after multiple attempts (if applicable). This is a permanent status; it will not change. You may wish to resend the fax.

Status Codes

Value Description Comments
-11 Pre-processing The system has received your message and is preparing a fax. This is a temporary status. Query again later to get a final status.
-1 Pre-processing The system has received your message and is preparing a fax. This is a temporary status. Query again later to get a final status.
-2 Ready The fax has been prepared and is awaiting its turn in the outbound queue. This is a temporary status. Query again later to get a final status.
-3 Sending (or pending retry) The fax is in the process of being sent or awaiting its next attempt. This is a temporary status. Query again later to get a final status.
-22 Out of credit, awaiting topup The fax is being held until credit becomes available in the account. To release the fax, login to your InterFAX account, click Purchase -> Prepaid Cards, select your required prepaid package, and proceed to checkout. Temporary status. The status may change on two conditions: a.) additional credits are bought within the account, or b.) 24 hours have passed without additional credits being bought, in which case the status will change to 205000. This is a temporary status and may subsequently change if credits have been bought.
Any other negative number Fax is being handled The system has received your message and is preparing a fax. This is a temporary status. Query again later to get a final status.
0 OK (Fax successfully sent) Your fax has been sent successfully. Note that this confirmation is provided by the receiving fax machine, indicating it confirms that it has received all pages successfully.
1 Internal error Call disconnected after several minutes without getting a page break or confirmation from the sender/receiver.
256 Internal error If you come across this error, please contact support for clarification.
263 Busy The receiving line is in use.
403 Fax manually canceled.
3072 Telephony error See *
3080 Telephony error See *
3211 Fax machine incompatibility See **
3220 Fax machine incompatibility See **
3223 An unexpected disconnect command was sent
3224 The remote fax machine failed to respond
3225 Fax machine incompatibility See **
3230 A disconnect message was received while attempting to negotiate transmission
3231 Fax machine incompatibility See **
3233 Fax machine incompatibility See **
3264 Fax machine incompatibility See **
3267 Fax machine incompatibility See **
3268 Transmission error (after page break)
3269 Fax machine incompatibility**
3300 Telephony error See *
3510 Telephony error See *
3830 Telephony error See *
3912 Phone number not operational No answer tone detected. The program is unable to classify incoming signals (i.e., there was no busy condition, no ring, no audio energy was detected.
3931 Busy The receiving line is in use.
3932 Phone number not operational Fast busy. The receiving line might be out of order or disconnected.
3933 Busy Unassigned number or telephony error.
3935 No answer (might be out of paper)
3936 Human voice answer
3937 Ring busy A ringing condition was detected followed by a busy signal.
3938 Phone number not operational
6001 Phone number not operational Unassigned Number?
6002 No route available May occur in developer accounts and free evaluation accounts when faxing to expensive locations. Contact support for assistance.
6003 Telephony error See *
6004 Telephony error See *
6016 Telephony error See *
6017 Busy The receiving line is in use.
6018 No answer (Might be out of paper)
6019 Telephony error See *
6021 Call rejected
6022 Number changed
6027 Phone number not operational Invalid number format?
6028 Phone number not operational Unassigned number
6029 Call rejected
6031 Telephony error See *
6034 Telephony error See *
6038 Telephony error See *
6041 Telephony error See *
6042 Telephony error See *
6043 Telephony error See *
6044 Telephony error See *
6047 Telephony error See *
6050 Telephony error See *
6054 Telephony error See *
6057 Telephony error See *
6058 Telephony error See *
6063 Telephony error See *
6065 Telephony error See *
6069 Telephony error See *
6079 Telephony error See *
6088 Incompatible destination
6095 Incompatible destination
6097 Incompatible destination
6099 Incompatible destination
6100 Incompatible destination
6102 Telephony error See *
6111 Telephony error See *
6127 Telephony error See *
7004 Telephony error See *
7012 Telephony error See *
7013 Telephony error See *
7200 Unspecified fax failure
8010 The remote fax machine hung up before receiving fax
8021 No answer Might be out of paper
8025 Busy The receiving line is in use.
204000 Rendering error The system could not turn your documents into a fax. Make sure your documents contain no macros, that they are not password-protected, and that they are in our list of supported file types.
204001 Rendering error The system could not turn your documents into a fax. Make sure your documents contain no macros, that they are not password-protected, and that they are in our list of supported file types.
205000 Quota exceeded (Prepaid card depleted) You need to purchase more faxing credits to send additional faxes. Login to your InterFAX account, click Purchase -> Prepaid Cards, select your required prepaid package, and proceed to checkout.
205001 Internal System error (FindRoute) Something unexpected has happened. Please contact support.
206001 Internal System Error (LocalSender) Something unexpected has happened. Please contact support.

* “Telephony Error” can have a variety of meanings and sources, which are mostly related to the setup of a call. A failure on “telephony error” does not necessarily mean that your fax will never be successfully transmitted. InterFAX records your initial error message and will attempt to route your fax through different servers on different phone lines, which may make subsequent attempts successful.

** “Fax Machine Incompatibility” means that the communication between InterFAX and the recipient did not succeed even though the call was answered by a fax machine. It is possible that some pages or partial pages did go through successfully. Please check for the ‘Pages’ indicator in the confirmation message that was sent to you.

Workaround for importing InterFAX security certificate into Microsoft Outlook

Nov 2004: It has been brought to our attention that some InterFAX clients are experiencing problems importing the InterFAX security certificate into Microsoft Outlook (Outlook Express does not reportedly exhibit this behavior). Importing the certificate is only necessary if encrypting emails sent to the InterFAX email-to-fax service.

Please follow these steps to work around this problem:

I. Request an InterFAX Certificate

This page explains how to do it.

II. Export the InterFAX Certificate:

  • 1. Open the signed mail received from InterFAX Secure.
  • 2. Click on the “secured” symbol to view the certificate (appears on the top-right corner of the mail message).
  • 3. If prompted, press “Details…”.
  • 4. Double click “signer: “send@fax.tc
  • 5. Click “View Certificate”
  • 6. Choose the Details tab and click “Copy to file”
  • 7. A new window will appear: “Welcome to the Certificate Export Wizard”, click “Next”.
  • 8. Keep the default setting: “DER encoded binary…”, click “Next”.
  • 9. Choose a location on your computer to save the certificate. You will need to remember this location for the import process later. For example: My Documents\InterfaxCert.cer, Click “Next”.
  • 10. Click “Finish” to complete the process.
  • 11. You should see a message box: “The export was successful”, Click “OK”
  • 12. Click “OK”, “Close” and “Close” (if exists, click “Close” again) on previously opened windows.

III. Import the InterFAX Certificate:

  • 1. In the mail message from InterFAX Secure, right-click our “From” address and select “Add to Address Book”
  • 2. Your address book will open on this newly-created entry. Click the “Digital IDs” tab and click “Import…”
  • 3. Locate the previously exported certificate and click “Open”.
  • 4. The “Certificates (Digital IDs)” window should show the certificate “Secure InterFAX Inc.”.
  • 5. In case a previous certificate was installed it is important to mark the new certificate as default (Click “Set as Default”).
  • 6. Marking a certificate and clicking “Properties” will show the certificate’s properties.

Problem: “The Internet Fax Service Requires MS Outlook 2003”

If you get the following popup notification when attempting to send a fax from Office 2003, scroll down to see the solution.

The problem is that even though you may have Outlook 2003 installed and even though you have activated it to work with InterFAX, Outlook is not configured as your default email program.

Here’s how to turn Outlook into your default email program:

From within Internet Explorer click Tools -> Internet Options (alternatively, from the Control Panel, click Internet Options), then select the “Programs” tab and select “Microsoft Office Outlook” as your email client. Click “OK”.

Understanding InterFAX outbound fax transmission confirmation formats

When you send faxes through the InterFAX email-to-fax service, you may choose to receive confirmations. You can select to receive confirmations on success of a transaction, on failure, always, or never. This setting can be viewed and changed by logging into your InterFAX account and clicking Preferences -> Outgoing, and scrolling down to the Authentication & Feedback section.

These confirmations are standard email messages which are returned to the original sender address of the email-to-fax. Different formats of these confirmations are available and will be discussed here.

Confirmation Option: Plain Text

This returns a human-readable message with no HTML formatting. See the field descriptions below for an explanation of fields.

Confirmation Option: HTML – Local Language

This returns a human-readable email with both a text part and an HTML part. HTML-capable email programs will display only the HTML part. The content will be in the default language of the InterFAX partner handling your account.

See the field descriptions below for an explanation of fields.

Confirmation Option: HTML – English

This returns a human-readable email with both a text part and an HTML part. HTML-capable email programs will display only the HTML part. The content will be in the English. See the field descriptions below for an explanation of fields.

Confirmation Option: CSV

This returns a machine-readable email, with details of your transaction as comma-separated values. The content fields are: TransactionID, CSID, PagesSent, Status, OriginalSubject, DestinationFax, Duration, SubmitTime, CompletionTime, Contact. See the field descriptions below for an explanation of fields.

Confirmation Option: XML

This returns a machine-readable email, with details of your transaction as an XML structure. An example structure is given below. See the field descriptions below for an explanation of tags.


<?xml version="1.0" encoding="utf-8" ?>

   12345678
   PRODI'S PIZZA
   1
   0
   Online Pizza Order #5696523
   0013447974477
   52
   2005-12-07 13:45:01
   2005-12-07 13:47:41
   John Moore

When submitting a fax broadcast, a slightly more complex structure is returned, with the following format:

<?xml version="1.0" encoding="utf-8" ?>

 
    TransactionID
    CSID
    PagesSent
    Status
    OriginalSubject
    DestinationFax
    Duration
    CompletionTime
    CompletionTime
    Contact
 
 
    TransactionID
    CSID
    PagesSent
    Status
    OriginalSubject
    DestinationFax
    Duration
    CompletionTime
    CompletionTime
    Contact
 
 
    TransactionID
    CSID
    PagesSent
    Status
    OriginalSubject
    DestinationFax
    Duration
    CompletionTime
    CompletionTime
    Contact
 
...

Field Descriptions

Field/Tag Description
TransactionID The transaction ID of the fax in the InterFAX system. This is a unique identifier. Note that individual faxes sent to recipients in a fax broadcast each have a distinct transaction ID.
CSID Calling Station Identifier. This is the identifier set on the destination fax machine. Every fax machine can be programmed with its own identifier which includes up to 23 letters and digits.
PagesSent The number of complete pages successfully sent. Partially-sent faxes will display a number smaller than the number of pages originally submitted.
Status The result of the fax transmission. In human-readable confirmations, this will be spelled out in words. In machine-readable confirmations, see the list of InterFAX Error Codes.
OriginalSubject The text inserted into the subject line of the outgoing email-to-fax. This is for reference only and is not used by InterFAX. Note that advanced modifiers, such as /b, are removed from the information returned here.
DestinationFax The destination fax number in international canonical format.
Duration The duration in seconds of the outgoing fax.
SubmitTime The date and time at which InterFAX received this fax for transmission. In ISO 8601 date/time format, i.e. yyyy-mm-dd hh:mm:ss.
CompletionTime The date and time at which InterFAX completed handling of this fax, whether succesfully transmitted or not. In ISO 8601 date/time format, i.e. yyyy-mm-dd hh:mm:ss.
Contact This field is populated online when sending a broadcast using InterFAX’s online list management system. In such a case, it includes the value of the Contact field of the respective entry.