Start a workflow when an email arrives

Use the inbound email address of a workflow so vendor bills or remittances sent to it start a run, with the email and attachments as input.

At the end of this page your workflow will have its own email address. Each email sent to it that passes your filters starts a run, with the email and its PDF attachments available to the steps.

This suits work that already arrives by email, such as vendor bills sent to an AP inbox or remittance advice from customers.

Before you start

Open the workflow in the editor.
Decide who may send to the address. You can limit it to named senders.

Set up the inbound address

Add the Inbound Email trigger

In the block list, open Triggers and drag Inbound Email onto the canvas. It replaces the current trigger.

Set filters, if you want them

Choose the trigger block. Under Filters you can set:

Sender allowlist (optional): only emails from these addresses start a run. Type an address and press Enter.
Subject contains (optional): only emails whose subject contains this text, such as "Invoice".
Require attachment: only emails with at least one PDF attached.

Leave them empty to accept every email sent to the address.

The email: sender, subject and body.
PDF attachments: each PDF up to 25 MB is saved to Files, and later steps can read it. Other file types are skipped.

A common next step is reading the bill. See Read PDF documents and Read, extract and classify with AI.

Good to know

Anyone who has the address can send to it. Share it only with trusted senders, and use Sender allowlist (optional) for vendor bills.
When a sender allowlist is set, Loopfour also drops emails that fail the standard checks that the sender's domain really sent them.
The address stays the same each time you deploy. If you archive the workflow, its address stops working. When you unarchive and deploy it again, it gets a new address, so send the new one to your senders.
Emails sent while the workflow is Draft, Paused or Archived do not start a run.

Check it worked

Send a test email with a PDF to the address.
The run appears under Runs, and the PDF appears under Files.

If something goes wrong

No run appeared. Check the workflow is Active, and that the email matches each filter you set. See A workflow did not run.
The run has no attachment. The file was not a PDF, or it was larger than 25 MB.