When I think of the word "letter," my brain goes old school to calligraphy and personalized wax stamp seals. My initial sketches were horrible attempts at something scripty. While I love beautiful hand-lettered logos, I know that it wouldn't represent the identity I was going for.
I started thinking about other components to letters and started to sketch variations of stamps. I wanted to keep things modern, clean, and minimal so I decided to go with the three wavy lines that verify if a letter has been paid for. This part of the logo represents authenticity. For the name, I decided to go with a bold, all-caps, sans-serif font.