When users subscribe using Navayan Subscribe their username is the same as their email address without the '@' sign.
For example Paul Smith subscribes as firstname.lastname@example.org. Navayan Subscribe adds him into the user base as paul.smithexample.com. Not good. Pretty ugly even considering that I cannot change usernames. I would have to delete the user and then re-add the user with a 'normal' username like 'PaulS'
I also tried to contact the author of Navayan on her blog, but the "Subscribe to my blog" will not allow me to put in a username!