New staff member with the exact same name, keep getting his emails, any advice?

[s3484711]

So a staff member started a fews of weeks ago with the exact same name as myself. I've been bombarded with his emails and have replied back obviously saying that they've got the wrong Lachlan, please take me off this mailing list. I reached out to him on LinkedIn, he doesn't know what to do, doesn't seem to motivated to change this situation. 

It's pretty annoying, anything I can do? Would love if he started using his middle name as his last or something, but you can't force that on people, some people don't like their middle names.