EssentialFax will work with most common faxmodems (the dialup kind), but we have often found the following modems to be problematic:
Conexant SoftK56 modems
Motorola SM56 modems
PCtel modems
ESS modems
Creative Modem Blaster modems
Intel HaM modems (and other modems of the HaM variety)
Lucent Win modems
LT Win modems
Ambient HaM modems
Conexant USB D400 (distributed with some DELL systems)
This modem does not do well with fax receiving, although it works fine for fax sending. If the modem answers incoming calls, but fails to establish a fax session and ends with a Fatal Timeout Error - some customers report success using a transfer rate of 4800 for Item # 16 in Preferences.