When is % not equal to %? When you're using the LIKE statement in SQL Server Reporting Services. If you've used the LIKE statement but haven't felt the love, it's because the standard wild-card operator (%) for a LIKE statement isn't the same in SSRS. Instead of the % operator they use *.
So the statement:
WHERE Customer.Email LIKE '%' + @qEmail + '%'
should instead be:
WHERE Customer.Email LIKE '*' + @qEmail + '*'