One of the best features of CoSender is the tracking of results and the ability to create multiple campaigns. I do like how easy it is to use and the customer care team is great. I have only experienced minor problems with CoSender. Nothing major but when you're sending out a lot of messages to a lot of people you do run into issues. Keep up with the updates and you won't have any problems! I am solving problems of getting to send emails to a lot of people, I have a lot of clients and I have to send out multiple newsletters to them. I am also able to keep track of who I sent an email to and who clicked on or open the email. I am able to get results back in under 24 hours.