Sitting down to write a letter you won't be alive to see opened is one of the strangest and most generous things you can do. Strange because it asks you to imagine a future you won't be part of. Generous because it gives the people you love something nothing else can: your voice, on a day they need it most.
It doesn't have to be long. Some of the most powerful letters are a single page. What matters is not the length — it's the honesty.
What to actually write
Tell them what they meant to you — specifically, not generally. Not 'you were everything to me' but 'I still think about the afternoon you called me just to talk, and I didn't say it then but it was one of the best days of my year.'
Share something you learned that took you too long to understand. Give them permission to grieve, and then to move on. Tell them what you hope for them — not what you expect, but what you genuinely hope.
If there's something unresolved between you, say it. A letter like this can carry an apology, an explanation, or just an acknowledgement that things were complicated. Don't use it to wound. Use it to close.
The one thing most people forget
Most people write the letter. Few people make sure it arrives. A letter in a drawer depends on someone finding it, recognizing what it is, and knowing it's for them. That's a lot of luck.
Write it somewhere that delivers it. EternalSelf's scheduled messages let you address a letter to a specific person, set a date or a trigger — like the first Christmas after you're gone — and trust that it reaches them. The letter you wrote deserves better than a drawer.