How to setup outgoing faxing with VoIP


This guide explains how to setup outgoing faxing with VoIP

Applicable to

All VoIP administrators


You must be a Sherweb VoIP Cloud Services user

How to

To use the outgoing fax service, customers can send an email to with the destination fax number in the subject line (including the 1 prefix – ex:15551234567) and the fax content attached as a .pdf.


Note: There is a limit of one attachment per fax- multiple documents must be faxed individually.


At least one authorized sender must be added to the E-Mail field in the account of the phone number that is used for faxing.

You can, however, authorize multiple senders by adding multiple addresses in the E-Mail field, separated by a comma and a space. Only addresses in this field will be able to send outgoing faxes through this account.


Fax-to-email limitation 

Fax-to-email (and fax over VoIP) is a cost-effective solution for occasional business faxing. However, Fax-to-email has known limitations and is very sensitive to the packet loss and compression that may occur when a fax is transmitted through various public telephone and internet networks carriers.


For heavy fax users, such as those in the financial sector, insurance, law and health care, we recommend maintaining an analog landline and a traditional fax machine for reliable and consistent performance.


Please contact support if you require assistance.



VoIP, Fax, outgoing, Cloud PBX