If you are an old-fashioned folk like me, you will probbably use LaTeX instead of Microsoft Office or LibreOffice to write your letters. Although there have been some successor document classes to write letters in LaTeX, I still prefer the g-brief class most. The problem is that with my printer the letter head is too close to the top page margin, while space reserved for the footer section looks way too large on the printed letter.
The best way to quickly rectifiy this is to edit the class file of g-brief, which is situated at /usr/share/texlive/texmf-dist/tex/latex/g-brief. Edit the line setlength \topmargin{-12.69mm} by changing the value to -2.69mm (or whatever is appropriate for your specific printer). Once this is done, both header and footer look more appropriately located.