Verizon has sent out information to its corporate customers with more specifics about its iPhone pre-orders and launch. According to an e-mail received by Mac Rumors, Verizon will begin accepting pre-orders from existing customers at 3:00 a.m. Eastern Time on February 3. The e-mail states that customers will need to have their My Verizon self-serve account set-up online prior to the opening of the pre-order window, as orders can only be placed through a My Verizon account. Existing customers will be able to order upgrades and new lines, although the e-mail also notes that the pre-sale inventory is limited, so customers who miss out will need to wait until the official launch on February 10. Finally, the report states that Verizon is allowing some existing AT&T customers to trade-in their iPhones for credit when buying a new Verizon iPhone 4, at a rate of $60 for a 16GB original iPhone, $105 for a 16GB iPhone 3G, $160 for a 32GB iPhone 3GS, $280 for a 16GB iPhone 4, and $360 for a 32GB iPhone 4. Verizon will be shipping its iPhones two-day FedEx, with next day air as an option.