What is the exact problem?
Are you not allowed to register (which should not be the case) or not allowed to download the tool?
There are some countries with which Xilinx does not allow to download tools. Check out Xilinx forums for details (your registration should be allowed, so you should be able to post your problem there).
I have a Xilinx ID for my personal projects done at home on my PC and is registered with my personal mail ID. I have renewed the node-locked licenses over the years and receive the new license file on this personal ID every time. You mail ID should not be an issue.