Source: https://cli.nylas.com/guides/payment-reminder-emails-cli

# Send Payment Reminder Emails from CLI

You need to chase unpaid invoices without buying your billing platform's email add-on. This guide schedules dunning emails with one command, gates each send on a live invoice status check in a bash script, and cancels the reminder the moment the invoice is marked paid.

Written by [Nick Barraclough](https://cli.nylas.com/authors/nick-barraclough) Product Manager

Reviewed by [Qasim Muhammad](https://cli.nylas.com/authors/qasim-muhammad)

Updated June 9, 2026

> **TL;DR:** Schedule a dunning email with [`nylas email send --schedule`](https://cli.nylas.com/docs/commands/email-send) and gate it on a live invoice status check in a few lines of bash — no per-seat billing-platform email add-on. One step keeps you from emailing a customer who already paid; it's the status gate in the section below.

## How do I send a payment reminder email from the terminal?

Send a payment reminder email by passing the customer address, a subject, and the overdue amount to `nylas email send`. Delivery goes over your connected provider's API, so there is no SMTP host, port, or app password to configure. The `--yes` flag skips the confirmation prompt so the command runs unattended in a cron job.

```bash
nylas email send \
  --to ada@acme.com \
  --subject "Invoice INV-1042 is 7 days overdue" \
  --body "Hi Ada, invoice INV-1042 for \$480.00 was due on 2026-06-02. Please pay at your earliest convenience." \
  --metadata invoice_id=INV-1042 \
  --yes
```

That one command replaces the email add-on most billing platforms sell as a paid tier. It works the same across Gmail, Outlook, and any IMAP account, so a single script chases invoices regardless of which mailbox sends them. The `--metadata` pair tags the message with the invoice ID for later correlation.

## How do I schedule a dunning email for a future date?

Schedule a dunning email with the `--schedule` flag, which accepts a relative duration like `3d`, a clock time like `9am`, or an absolute date. Nylas holds the message and sends it at that time, so a single command queues a reminder days ahead without keeping a process running.

```bash
# Queue a first reminder 3 days from now
nylas email send \
  --to ada@acme.com \
  --subject "Reminder: invoice INV-1042 due soon" \
  --body "Hi Ada, invoice INV-1042 for \$480.00 is due 2026-06-02." \
  --metadata invoice_id=INV-1042 \
  --schedule 3d \
  --yes
```

A classic dunning ladder sends three reminders — for example at 3, 7, and 14 days past due — with the tone escalating each time. Queue all three at once, then list pending sends with `nylas email scheduled list` to confirm they are in the queue before you walk away.

## How do I stop a reminder if the invoice is already paid?

Gate the send on a live status check: call your billing API, read the invoice state, and only run `nylas email send` when the status is still unpaid. This single conditional is what separates a useful reminder from the embarrassing mistake of dunning a customer who settled the bill an hour ago.

```bash
#!/usr/bin/env bash
set -euo pipefail

INVOICE_ID="INV-1042"
CUSTOMER="ada@acme.com"

# Ask your billing system for the current status (returns "paid" or "open")
STATUS=$(curl -fsSL \
  -H "Authorization: Bearer $BILLING_TOKEN" \
  "https://api.billing.example.com/invoices/$INVOICE_ID" \
  | jq -r '.status')

if [ "$STATUS" = "open" ]; then
  nylas email send --to "$CUSTOMER" \
    --subject "Invoice $INVOICE_ID is overdue" \
    --body "Your invoice $INVOICE_ID remains unpaid. Please settle it today." \
    --metadata invoice_id="$INVOICE_ID" --yes
else
  echo "Invoice $INVOICE_ID is $STATUS — skipping reminder"
fi
```

Run this script from cron on a daily cadence. Because the status read happens at send time, a customer who paid yesterday gets nothing today. The `set -euo pipefail` line makes the script exit on the first error, so a failed API call never silently sends the wrong reminder.

## How do I cancel a scheduled reminder when payment arrives?

Cancel a queued reminder with `nylas email scheduled cancel` and the schedule ID. When a webhook or a status poll tells you an invoice was paid, pull the pending sends, find the one tagged with that invoice, and cancel it. This closes the gap where a reminder is already in the queue before payment lands.

```bash
# List pending scheduled sends as JSON, then cancel by ID
SCHEDULE_ID=$(nylas email scheduled list --json \
  | jq -r '.[0].schedule_id')

nylas email scheduled cancel "$SCHEDULE_ID" --force
```

The `--force` flag skips the confirmation prompt so the cancel runs inside an automated payment-received handler. Together with the status gate, this gives two layers of protection: the gate stops new sends, and the cancel pulls back reminders already scheduled for the next 14 days.

## What should a dunning email say, and what are the limits?

A payment reminder email should state the invoice number, the amount, the original due date, and a single clear payment action. Keep early reminders friendly; reserve firm language for the final notice. Reusable copy belongs in a stored template so the wording stays consistent across every invoice and every teammate who triggers a send.

```bash
# Render a hosted template with invoice data instead of inline copy
nylas email send --to ada@acme.com \
  --template-id tpl_dunning_overdue \
  --template-data '{"invoice":"INV-1042","amount":"$480.00","due":"2026-06-02"}' \
  --metadata invoice_id=INV-1042 --yes
```

Know the legal line. If you collect debts on behalf of others in the United States, the [FDCPA (Regulation F)](https://www.consumerfinance.gov/rules-policy/regulations/1006/) governs frequency and content. A business chasing its own invoices is usually outside that scope, but the rule's 7-in-7-days contact limit is a sensible ceiling to respect anyway. When you send bulk reminders, include a one-click unsubscribe header per [RFC 8058](https://datatracker.ietf.org/doc/html/rfc8058) to protect sender reputation.

## Next steps

- [Send Yourself Follow-Up Reminders](https://cli.nylas.com/guides/follow-up-reminder-email-cli) — Find sent threads with no reply via nylas email threads and…
- [Send email from a bash script](https://cli.nylas.com/guides/send-email-from-bash-script) — the scripting patterns behind the status-gated send above
- [Schedule email from the terminal](https://cli.nylas.com/guides/schedule-email-from-terminal) — full reference for `--schedule` timing and canceling queued sends
- [Email templates from the CLI](https://cli.nylas.com/guides/email-templates-cli) — keep dunning copy consistent across every invoice
- [Tag emails with metadata](https://cli.nylas.com/guides/tag-emails-with-metadata-cli) — correlate each reminder to its invoice ID for reporting
- [Getting started with Nylas CLI](https://cli.nylas.com/guides/getting-started) — connect your first account in under 5 minutes
- [Command reference](https://cli.nylas.com/docs/commands) — every flag, subcommand, and example
- [CFPB Regulation F](https://www.consumerfinance.gov/rules-policy/regulations/1006/) — the debt-collection rule that bounds frequency and content
- [Gmail API documentation](https://developers.google.com/workspace/gmail/api) — the provider API the CLI sends over for Gmail accounts