Use case

Pull invoice due dates and amounts straight out of your email

Invoices arrive as ordinary emails, with the due date buried in a sentence somewhere. PlainMailOS recognises invoice emails, extracts the vendor, amount and due date, and warns you as the deadline approaches, so a late fee never comes from an email you simply did not see.

The problem with invoices that live in your inbox

Most small businesses and freelancers receive invoices and payment reminders by email. There is no central list, so what you owe is scattered across threads, and the due date is easy to miss when it sits in the body of a message rather than in a field.

  • Due dates are written as sentences, not structured data.
  • Reminders arrive between dozens of unrelated messages.
  • Nothing tells you which invoices are about to become overdue.

What PlainMailOS extracts

When an email looks like an invoice or a payment request, PlainMailOS files it under Finance and reads the message for the details that matter: the vendor, the amount with its currency, and the payment due date.

Amounts are handled in the right currency format, including currencies without decimal places, so a figure is not misread by a factor of one hundred.

  • Vendor: who is asking to be paid.
  • Amount and currency.
  • Due date and whether the invoice is already overdue.

Alerts before it becomes a problem

PlainMailOS raises an alert when an invoice is due within a week or is already overdue. An overdue invoice is marked critical, so it stands out from routine reminders.

A summary of what you owe and what is overdue gives you the whole picture without opening a single thread.

Where it has limits

PlainMailOS reads the text of your emails. If the details appear only inside an attached file, they may not be picked up, and an unusual invoice layout can be missed. When a detail matters, check it against the original email.

Questions

Does PlainMailOS pay my invoices?+
No. It finds them, extracts the due date and amount, and alerts you. Payment stays with you.
Does it handle different currencies?+
Yes. Amounts are read in the currency they are written in, with the correct decimal handling for each currency.
Which email accounts does it work with?+
Microsoft 365 (work or school) accounts and IMAP mailboxes. Gmail support is coming soon.

Know what you owe before it is due

Start a 14-day free trial, connect a Microsoft 365 or IMAP mailbox, and let PlainMailOS watch for invoices.

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Last reviewed 2026-10-04.