dqs - matching in only one column

I want to use dqs for matching on one column and I am having a hard time…

I have an 8 million records table… If I don’t use it with a ‘prerequisite’ it never ends (takes more than 100 hours)…

So, it’s a Contacts table and I want to do a matching just on ‘email’ column… it has a lot of repeated values…

Table structure:

-email

-name

-lastname

-address

-id1

-id2

-prod

I know I could just use tsql, but I like about DQS that I can pick the survivor as the most complete record…

Why dqs is not allowing me to do a match on only one column?! Makes no sense!