LetterAgent
Mail physical letters by just asking your AI assistant.
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Online mailing tools validate your address against the postal service's official address database, and they reject anything that doesn't match exactly. The usual culprits: a missing apartment or suite number, a misspelled street name, or a brand-new address the database hasn't caught up with yet. Fix the address to match the official record and it goes through.
| Rejection reason | What's actually wrong | Fix |
|---|---|---|
| Missing unit number | The database knows the building has units; your entry didn't name one | Add the apartment, suite, or unit number exactly as the building lists it |
| Street name mismatch | Abbreviation or spelling differs from the official record ("St" vs "Street", "McDonald" vs "MacDonald") | Copy the address from the postal service's own lookup tool |
| New construction | The building exists but the address database hasn't been updated yet | Wait, or use the developer's postal address until the record appears |
| Rural route vs street address | The database lists one format; you entered the other | Use whichever format the postal lookup returns |
Address databases update on the postal service's schedule, not the builder's. A new subdivision can have residents for months before every address is in the system, and commercial databases used by online tools can lag further still. If your address is genuinely new, this isn't your typo: it's a timing gap. The workaround is mailing to the address the system does recognize (a leasing office, a PO box) until your address appears, or having the recipient confirm the exact official formatting with their local post office.
Because the validation is strictest where delivery is hardest. A missing suite number on a single-family home is obvious to the carrier; a missing apartment number in a 40-unit building is a dead end. The database flags unit-less addresses in multi-unit buildings aggressively, and some tools reject them outright rather than risk an undeliverable. Always include the unit designator, and put it in the secondary address field (apartment, suite, unit) rather than cramming it onto the street line, where parsers misread it.
Addresses are verified automatically when a letter job is created: if the address doesn't validate against the postal database, it's caught then, before anything is printed. That's deliberately early in the flow, while fixing it is free. If your address gets flagged, double-check the unit number and the exact street spelling against the postal service's lookup tool, then resubmit. A rejected address is the system protecting you from paying for a letter that would come back.
Ready to mail it? Send your letter with LetterAgent: describe it to your AI assistant, approve the exact quoted price, and it's 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