Is this a Valid Email "xyz@abc.com.com.com.com" ? I have seen Email IDs like "xyz@yahoo.co.in"
You may replace .COMs with some other string.
The point is How many sub regional domains can an Email ID have ?
I am planning to mark an Email field in my project as a bug. I normally mark them as bug if there are more than 3 parts separated by . symbol after the @ symbol.