I woke up this morning to 186 unread emails on my cellphone. Why?

It started about 2 months ago, for no reason i started getting meaningless junk emails sent to my AU smartphone. Most of them were sexual in nature. I tried to add most of them to a rejection list, that seemed to help, but all of the sudden a huge flood of them came. 186 in the course of 7 hours. they keep coming, once a minute or so...

I don't really want to change my email address, are there any other options?