I dint understand what to do

Question

Consider that email IDs are supposed to be for the following format:
[e-mail].
Here, there are three conditions to keep in mind:
1. The username can only contain characters 0-9, a-z and A-Z.
2. The website name can contain only characters a-z
3. The extension can have 2 or 3 alphabets(a-z).

Answer 1

Is this some homework?
I think you have to do something that generates a random email ID?

Answer 2

You probably need to write a regular expression to check if it's correct. have fun