Its redundant espeically in this case.. I agree with you, a id column is needed but only when its required.

And you can figure out if you need an ID column by normalization.

I just want to point out that not every table requires an ID column. In this case an emailid (email address) field is a perfect example.

Most of my tables also use a GUID for a primary key where normalization would not lead to a two or more part primary key.