Two separate column counts grouped by one of those columns
To count rows:

COUNT(*)


To count non-null values in a column:

COUNT(email)


To count non-null values, without counting the empty strings:

COUNT(CASE WHEN email &gt; '' THEN email END)    -- or
COUNT(CASE WHEN email &gt; '' THEN 1 END)        -- or
SUM(email &gt; '')                               -- or
COUNT(email) - SUM(email = '')