Plunk Documentation

Plunk can receive emails sent to your verified domain and turn them into email.received events. This allows you to build automated workflows that respond to inbound emails, such as support ticket systems, auto-responders, or email-based integrations.

How it works

When someone sends an email to your verified domain (e.g., support@yourdomain.com or hello@yourdomain.com), Plunk will:

Receive the email through AWS SES
Automatically create or update a contact for the sender
Trigger an email.received event that can start workflows
Make the email metadata available to your workflow steps

The sender is automatically added to your contacts as a subscribed contact, allowing you to respond using Plunk's email sending capabilities.

Setting up inbound email

Verify your domain

Before you can receive emails, your domain must be verified in Plunk. Follow the verifying domains guide to set up the required DKIM, SPF, and MX records for sending.

Add the inbound MX record

In your project settings, navigate to the Domains tab and expand your verified domain. You'll see an optional "Inbound Email" section with an MX record configuration:

Type: MX
Name: yourdomain.com (your root domain)
Value: 10 inbound-smtp.eu-north-1.amazonaws.com

Add this MX record to your domain's DNS settings. The priority value 10 ensures that inbound emails are routed to AWS SES for processing.

Multiple MX records

If you're already using MX records for another email service (like Google Workspace or Microsoft 365), adding this MX record may conflict. You can only have one primary email receiver per domain. Consider using a subdomain (e.g., mail.yourdomain.com) if you need to maintain both services.

Wait for DNS propagation

DNS changes can take anywhere from a few minutes to 48 hours to fully propagate. You can verify the MX record is set correctly using:

dig MX yourdomain.com

You should see the AWS SES inbound endpoint in the response.

Creating workflows with email.received

Once your MX record is configured, you can create workflows that respond to incoming emails.

Event trigger

Create a new workflow and use email.received as the trigger event. This workflow will run every time an email is received at your domain.

Available event data

The email.received event includes the following data that you can use in your workflow steps:

Field	Type	Description
`messageId`	string	Unique identifier for the received message
`from`	string	Email address of the sender
`fromHeader`	string	Full "From" header including display name
`to`	string	Primary recipient email address
`subject`	string	Email subject line
`timestamp`	string	ISO 8601 timestamp when the email was received
`recipients`	string[]	All recipient email addresses
`hasContent`	boolean	Whether the email body was captured
`spamVerdict`	string	Spam check result (e.g., "PASS", "FAIL")
`virusVerdict`	string	Virus scan result (e.g., "PASS", "FAIL")
`spfVerdict`	string	SPF authentication result
`dkimVerdict`	string	DKIM authentication result
`dmarcVerdict`	string	DMARC authentication result
`processingTimeMillis`	number	Time taken to process the email

You can access these fields in your workflow using variable syntax, for example: {{event.subject}} or {{event.from}}.

Multi-project domains

If you have verified the same domain in multiple projects, incoming emails will be processed for all projects that have the domain verified. Each project will:

Create/update the sender as a contact in that project
Trigger the email.received event in that project
Run any workflows configured for that event

This allows you to segment inbound email handling across different projects if needed.

Limitations

Email body content

Currently, the email body content is not stored or made available in the event data. Only metadata (sender, subject, recipients, timestamps, and security verdicts) is captured. The hasContent field indicates whether body content was present, but the content itself is not accessible in workflows.

Catch-all addresses: Plunk receives emails sent to any address at your verified domain (e.g., anything@yourdomain.com). You can use workflow conditions to route emails based on the to field.
Attachments: Email attachments are not currently captured or stored.
Email size: AWS SES has a maximum message size limit of 40 MB for inbound emails.

Security considerations

Plunk captures several security verdicts for each incoming email:

SPF (Sender Policy Framework): Verifies the sender's mail server is authorized
DKIM (DomainKeys Identified Mail): Validates the email hasn't been tampered with
DMARC (Domain-based Message Authentication): Combines SPF and DKIM for additional validation
Spam verdict: AWS SES's spam detection result
Virus verdict: AWS SES's virus scanning result

You can use these verdicts in workflow conditions to automatically filter or quarantine suspicious emails before processing them.

Troubleshooting

Emails not being received

Check DNS propagation: Verify the MX record is correctly set using dig MX yourdomain.com
Verify domain: Ensure your domain is fully verified in Plunk (all DKIM, SPF, and MX records for sending)
Check workflow: Create a simple test workflow with just an email.received trigger and a webhook to verify events are being generated
Check sender: Try sending from a different email provider as some may cache DNS records

Duplicate events

If you have the same domain verified in multiple projects, you will receive duplicate email.received events (one per project). This is expected behavior. Use project-specific workflows to handle this.

Security verdicts failing

If incoming emails consistently show failing security verdicts:

SPF failures: The sender's domain may not have SPF configured correctly
DKIM failures: The sender's domain may not have DKIM configured, or the email was forwarded/modified in transit
DMARC failures: The sender fails both SPF and DKIM checks

These are issues with the sender's configuration, not your Plunk setup. You can choose to process these emails anyway or filter them using workflow conditions.

Receiving emails