The good news is you can use a gmail address as the sender in constant contact. Because you are sending through Constant Contact, your email is technically not being sent through this email client. The same sending limits that many email clients have do not apply. Though there is not a limit to how many contacts you can send to it is important to make sure you only send to contacts who have opt-in to receive your emails. If you have any further questions, our Account Review support is also available by phone to help find the answers you need!