SIF allows you to send messages to faxes, e-mail addresses, and phones(regular or mobile) from your PC via Internet and also save your money on sending faxes outside your local area. You also may use SIF for remote printing of your memos/ideas when you are on the road. SIF3 allows you to create contact lists with thousands of e-mails,fax/phone numbers and to send personalized messages to people on your contact lists. Known problems: On some networks it is not working. Please try it before paying for it.