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; however, please note that this list may change over time.

Outbound Service

Maximum number of pages per fax: 100 pages (more may be accommodated upon request).
Maximum number of email to fax recipients (total addresses in ‘To:’ and ‘Cc:’ lines.) per submission: 500 addresses.
Maximum number of recipients in a single submission (faxing via lists or submission via web service): 20,000 recipients.
Maximum total file size of fax attachments: 20 MB.
Maximum total file size of fax attachments, where the email is electronically signed: 10 MB.
Fax images are stored and visible for: 14 days.
For prepaid package users: Fax information is kept for 35 days after the prepaid card that was used at the time has been depleted.
For monthly subscription users: Fax information is kept for 35 days after the end of the month during which the fax was sent.
Maximum postpone time: 30 days.
Unable to support password-protected files.
Unable to support read-only files (which bring up a pop-up when opened).
Macros are disabled. Do not use macros, as they may affect document output.
Supported attachment file types: See Supported file types for a complete list of 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 Send Fax: 5 attachments.
Maximum frequency of polling for fax status: Up to 6 requests per minute.

An account manager may define up to 10 additional 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.
Users can store received messages and view them for 12 months. Extended storage period is available, please visit our pricing page for additional details.
Maximum frequency of polling for fax status: Up to 6 requests per minute.

Maximum request size of any type: 8 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.

Maximum request size of any type: 8 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.
Requests support UTF-8 encoding only.

Session idle timeout (time of inactivity before user is logged out): 15 minutes.
Response timeout: 90 seconds.
Maximum file size of fax image for downloading from the site: 4 MB
Maximum number of users per account (can be increased upon request): 500
Web browsers supported (most recent versions): Google Chrome, Mozilla Firefox, Microsoft Edge, and Safari.

Your password must:

Be between 7 - 16 characters in length.
Contain 3 of the following:
- Numeric characters
- Uppercase alphabet characters (A-Z)
- Lowercase alphabet characters (a-z)
- Special characters: ! @ # $ % ( ) " & ' * + -
Not reuse one of your 20 most recent passwords.
Not include your username.

Passwords are required to be changed every 90 days.

Users will be temporary suspended after 3 months of inactivity. Account Managers or Customer Support can reinstate these users upon request.