[Accounting integration]

Add postal mail to accounting and AP workflows

Use QuickBooks or Xero context for invoice follow-ups, tax correspondence, engagement letters, and payment-plan mailings, then keep mailed proof plus forwarded IRS, state, or client paperwork tied to the accounting workflow.

Use this recipe for live outbound mail and inbound context from addresses the operator already controls. New real mailing and package addresses with street address + mailbox number: Not live yet · Launch ETA: mid/late September. Route requests to the reservation list; reservations do not assign or activate an address today.

recommended shape
source app trigger
agent or code drafts
mailbox.bot dry run
approval gate
delivery webhook
address requests reserve spot
Best for
Accounting firms and AP teams that still need paper correspondence.
Invoice, tax, bill, vendor, and client workflows where delivery proof matters.
Teams that need one place to connect outbound mail with inbound mailed notices, scanned replies, or supporting document packets.
Triggers
Invoice remains unpaid after a threshold.
Tax notice or client packet is approved for mail.
Vendor or customer correspondence requires certified delivery.
[Workflow]
1

Accounting app, export, webhook, or agent supplies invoice, vendor, client, or notice context.

2

Packet is drafted and previewed with mailbox.bot dry_run=true.

3

Controller, partner, or client approves sensitive mail.

4

mailbox.bot sends and tracks the piece.

5

Webhook status, proof, and any forwarded inbound tax or client documents are stored back in the accounting workflow or client record.

Technical pattern
Use REST for direct send flows and MCP for agents drafting from accounting context.
Store invoice, customer, vendor, notice, and approval IDs in metadata.
Write mail_id, status, tracking, and proof back into the accounting-side record or companion database.
Metadata to preserve
source=quickbooks_xero
invoice_id
customer_id
vendor_id
notice_id
approval_id
POST/api/v1/maildry_run=true
curl -X POST https://mailbox.bot/api/v1/mail \
  -H "Authorization: Bearer sk_agent_test_..." \
  -H "X-Mailbox-MD-Version: 3" \
  -H "X-Max-Cost-Cents: 1500" \
  -F "document=@notice.pdf" \
  -F "recipient_name=Recipient Name" \
  -F "recipient_line1=123 Main Street" \
  -F "recipient_city=San Francisco" \
  -F "recipient_state=CA" \
  -F "recipient_zip=94105" \
  -F "mail_class=certified" \
  -F "dry_run=true" \
  -F 'metadata[source]=quickbooks-xero'
Agent prompts
"When an invoice is 45 days overdue, draft a mailed payment reminder through mailbox.bot and require approval."
"Turn this tax notice reply packet into a certified mail dry run with proof metadata tied to the client record."