This seems to work... If you post consumable data (create table scripts, and inserts), it's a lot easier for people to help you - since you've set up the problem for them. Then they can just bang out a solution easily. Like you see below. (you could copy the whole thing into a query window and run it and set up the problem). Makes helping you much easier.

use tempdb;

go

create table Contact(

empID int,

email varchar(30),

seq tinyint);

go

insert into Contact(empID,email,seq)

values (1,'t@t.com',1),(1, 's@s.com', 2),

(2, 'q@.com', 1),

(2, 'q@.com', 2),

(3, 'z@te.com', 1),

(3, 'Z@e.com', 2);

insert into Contact(empID,email,seq)

values (4,'b@te.com',2);

insert into Contact(empID,email,seq)

values (5, null,1),(5,'fifth@gin.com',2);

SELECT e1.EmpID, seq, email

FROM

-- get the first non-null sequence # where the email is not empty

(SELECT EmpID, MIN(seq) As MinSeq

FROM contact

WHERE email IS NOT NULL

GROUP BY EmpID) e1

INNER JOIN

-- join back to another copy of the table and retrieve what we want

(SELECT EmpID, seq, email

FROM contact) e2

-- use the join to do the filtering...

ON e1.empid=e2.empid

AND e1.minseq = e2.seq;

There's probably a neater way of doing this, but it's late and my brain is fried... but it works.