Sending a love letter is a way for your sim to court other sims and pique their romantic interests. Every time you click on your mailbox, you’ll see the option to ‘send a love letter’. You can also ‘send a love letter’ from your sim’s pc, or by clicking on the object of your sim’s affection in the friends menu.
No Writing Surface Available
This simply means that your sim has nowhere to sit down and write. This problem can be solved with a writing desk (not cluttered with a computer) or a kitchen table.