eFax Corporate is rated 4.8 out of 5 in the category fax service. Read and write reviews about eFax Corporate. Live Web Chat eFax Corporate is the world leader in digital faxing providing solutions for small and medium businesses and large enterprise companies since 1995. eFax services 11+ million customers worldwide, and nearly 50% of FORTUNE 500 companies depend on eFax for its business communications today. Cost-effective Faxing eFax Corporate provides a cost-effective alternative to fax machines and in-house fax servers, which enables employees to send and receive faxes by email . ...