Sql Table data type for email address?

you can use varchar as your data type for email column as emails are usually composed of letters, numbers and special characters.

It's good to go with NVARCHAR(320) - 64 characters for local part + @ + 255 for domain name.

You Use varchar(255) and nvarchar(255) Data type

Since the max lenght for a email is 254 characters, i would recommend you to use nvarchar(255). That should be enough