With just your contact's mobile number you can send them a professionally formatted, business-like letter, delivered as a single PDF document. All the address details and formatting are done for you (Free Service). In addition, you'll enjoy some unique features including: An Unlimited In Box capacity. The only mail system to use human intelligence to spot and stop spam. Automatic management of all your address book and correspondence. Delivery notifications by SMS (Premium Service). Password encryption for your entire letter (Premium Service). Up to 10Mb of attachments (Premium Service). Proof of delivery with the TIMX postmark. Guaranteed to be from the number it claims to be and easily checkable with a phone call.