LetterAgent
Mail physical letters by just asking your AI assistant.
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Yes, you can mail a letter for another person, but you should say so openly in the letter, sign in a way that shows you are acting for them, and hold their permission, especially for legal or financial matters. Mailing a letter is not restricted; pretending to be the other person is where trouble starts.
Mailing is a physical act anyone can do: dropping an envelope in a mailbox, or asking a service to print and mail it, does not claim you are the author. Signing someone else's name is different. It claims the signature is theirs, and doing it without authority can amount to forgery, even with good intentions. The safe pattern is transparency: the letter states who it is from, who wrote or authorized it, and who signed it. A common form is to sign your own name followed by "on behalf of" and the other person's name, or "for" and their name, so the recipient can see exactly what happened.
It depends on what the letter does. A birthday card mailed for a relative needs no paperwork. A letter that cancels a contract, closes an account, disputes a bill, or makes a legal claim on someone's behalf usually needs more: a written authorization, a power of attorney, or a role such as executor, guardian, or company officer that already gives you that authority. Banks, insurers, and government offices routinely ask to see that authorization before they act on a letter from a third party, and some will only discuss the account with the account holder directly, for privacy reasons. If you are unsure, ask the recipient what authorization they require before you send the letter, rather than after a rejection.
| Situation | What usually suffices |
|---|---|
| Personal letter, greeting, or thanks | Informal permission; say you mailed it for them |
| Business letter as an employee | Your job role; sign with your title |
| Letter for a family member | Their written permission, kept on file |
| Financial or legal action | Power of attorney or other formal authority |
| Letter for a deceased person's estate | Executor or administrator status, with proof |
Three parts, kept short. First, a line in the body or near the signature stating your relationship and authority: "I am writing on behalf of my mother, with her permission," or "As executor of the estate of..." Second, your own signature, not theirs. Third, your printed name and contact details, so the recipient can reply to the person who actually sent the letter. Never sign their name, never copy their signature, and never backdate a letter to make it look as if they signed earlier. If the recipient requires the person's own signature, the letter must go to them to sign first; there is no shortcut around that requirement.
Parents routinely mail letters for minor children, such as school or medical correspondence, and that is normal. For adults who cannot write or sign due to illness or disability, the rules vary by state and province, and some allow a mark witnessed by others, or a signature made at their direction in their presence. Those cases deserve a quick check of local rules before you act, because a letter signed the wrong way can be rejected exactly when it matters most. When in doubt, have the person sign if they can, even with assistance, and have a witness present.
Yes, in the same sense as mailing any letter: you describe the letter to your AI assistant, approve the exact quoted price, and it is printed and mailed to a US or Canadian address. LetterAgent does not check your authority to write for someone else, so that responsibility stays with you. Be transparent in the letter text itself about who you are acting for and why, and keep the person's permission with your own copy of the letter.
Ready to mail it? Send your letter with LetterAgent: describe it to your AI assistant, approve the exact quoted price, and it is printed and mailed.
LetterAgent is a working name. Prices include print, postage, and our service fee. US prices in USD, Canadian prices in CAD (Canadian prices exclude applicable sales tax, added at checkout). Currently in private testing.
Need help? Ask your assistant: it can check a job's status any time. If it ever can't handle something: hello@getletteragent.com