In case you are only using groupfaxes it could lead to problems when a user wants to send a fax. This will not be possible when these users are not part of a Faxgroup (or have no own faxnumber) even if they have a fax license .
This is due to the fact that a user cannot send a fax when he does not have a fax number (fax number means an internal and external fax number !).
How can this be solved?
Create a faxgroup with an internal and external number and add all users that need to send faxes. These users will now be able to send a fax. They will have to select "send on behalf of <faxgroup>" in the fax printer driver. In the same window they can select alo the number that should be in the header of the fax (so this is not necessarily the number of the fax group).