Are these emails being delivered to a web mail account or through a client like outlook? As a test you should try sending the emails to another account that is different from the type you are working with, for example if you are getting the emails in hotmail like this then maybe try sending them to your personal mail that goes to your outlook or some other web mail hosts.
This can help to pinpoint the problem further, please post back with this info and if needed I will log a ticket for you on this.
