Mailgun

Use Mailgun when you want Drip Drop to send email through a domain-based email delivery provider instead of a personal mailbox. Mailgun can handle outbound sending, event webhooks, engagement tracking, and inbound routing for replies.

Note
Mailgun is different from Gmail and Outlook. It is a domain-based email service provider, not a mailbox OAuth login flow.
  • You want application-style or domain-based email sending instead of sending from a mailbox account.
  • You want provider-side delivery, failure, complaint, unsubscribe, open, and click events in Drip Drop.
  • You want reply handling through Mailgun inbound routes on a parse domain instead of mailbox polling or OAuth inbox subscriptions.
  1. Confirm you have Mailgun account access and permission to work with domains, webhooks, and routes.
  2. Choose the Mailgun Sender Domain Drip Drop should send from.
  3. Decide whether you need only outbound sending, or also webhooks, Track Opens/Track Clicks, and inbound routing.
  4. If you want inbound replies, plan the parse subdomain or hostname that should receive those messages.
Choose Mailgun from the New Integration provider list.
  1. Open Integrations → Email.
  2. Click New Integration and choose Mailgun.
Name the Mailgun integration and enter its API key, sending domain, and optional IP pool ID.
  1. On Connect, enter the API Key and Domain. Enter IP Pool ID only if you already use a dedicated Mailgun pool.
  2. Select Save & Continue.
Review webhook status, verification controls, tracking options, and optional inbound settings.
  1. On Webhooks, choose Track Clicks, Track Opens, Enable Inbound Parse, and Enable Signed Webhooks as needed. Select Configure Webhook and Verify Webhook as needed, then select Save Webhook. To decline webhooks, select Skip for now.
Review the verified sender address available to the Mailgun integration.

On Senders, add at least one email address that flows can send from, or select Skip for now and add one later.

Confirm that credentials, webhook configuration, and a sender are present before finishing setup.

On Verify, use Check credentials and Verify webhook before selecting Done.

Domain tells Mailgun which sending domain to use. The sender email address is managed separately on Senders and selected in a flow.

  • Use a Domain that the stored API Key can access.
  • Outbound sending does not require event webhooks or inbound routing, but flows still need a sender email address.
  • IP Pool ID is optional. Use it only for an existing dedicated Mailgun pool; leave it blank to use Mailgun’s default routing.
  • Use Check credentials to validate the saved API Key and Domain together. The key must be able to access that domain.
  • Mailgun webhook configuration is domain-specific, so Configure Webhook and Verify Webhook use the saved Domain.

Helpful Mailgun references: Mailgun domains, Mailgun webhooks, and Mailgun routes.

Mailgun webhooks send delivery and engagement events from the sender domain back to Drip Drop. This is separate from inbound routes.

  • Drip Drop can use delivered, permanent fail, temporary fail, complained, and unsubscribed events from Mailgun.
  • Opened Events only appear when Track Opens is enabled.
  • Clicked Events only appear when Track Clicks is enabled.
  • Configure Webhook adds the Drip Drop URL to each selected event type and preserves existing URLs while space remains.
  • Mailgun allows three URLs per event type. If all three slots are already used, Configure Webhook keeps the two most recent existing URLs and replaces the oldest. Verify Webhook succeeds only when the Drip Drop URL is registered for every selected event type.

Track Opens and Track Clicks control whether Configure Webhook and Verify Webhook include Mailgun’s opened and clicked event types.

  • For open events, enable Track Opens in Drip Drop and open tracking in Mailgun. Mailgun also requires its tracking CNAME to resolve.
  • For click events, enable Track Clicks in Drip Drop and click tracking in Mailgun. Mailgun also requires its tracking CNAME to resolve.

Mailgun signs webhook payloads with a token, timestamp, and signature. Before enabling Enable Signed Webhooks, save the Webhook Signing Key in Drip Drop.

  • The Signing Key is separate from the main Mailgun API key.
  • When signed validation is enabled, Drip Drop rejects event and inbound-parse requests whose signature is missing or invalid, or whose timestamp is more than five minutes from the server clock.
  • Configure Webhook and Verify Webhook confirm URL registration, not signing-key correctness. Send a test event after saving the key to confirm signed delivery succeeds.

Mailgun inbound handling is route-based. Instead of mailbox polling or OAuth subscriptions, Mailgun receives messages on a parse hostname and forwards them to Drip Drop.

  • Enable Inbound Parse in the provider form if you want Mailgun-hosted reply handling.
  • Set the Inbound Parse Domain to the Hostname or Subdomain that should receive reply emails.
  • Drip Drop can attempt to create or update the Mailgun route automatically, but some accounts may still need manual route or DNS work in Mailgun.
  • Drip Drop uses the In-Reply-To tracking header to confirm a reply. Without that match, it may thread the message to the most recent outbound message sent to the sender, but the fallback does not create a REPLY event.
  1. Open the selected domain in Mailgun if Drip Drop cannot auto-configure webhooks.
  2. Add or verify the event webhook URLs for the event types Drip Drop needs.
  3. Enable Mailgun open and click tracking if you want those events. Keep Track Opens and Track Clicks enabled in Drip Drop so Configure Webhook and Verify Webhook include them.
  4. If signed webhook verification is required, copy the webhook signing key into Drip Drop.
  5. Open Mailgun routes or inbound routing settings if you need reply handling.
  6. Configure the Inbound route expression and forward action for the parse hostname, along with any required MX or DNS records for that hostname.
  • After webhook traffic starts arriving, Drip Drop can attach delivery and engagement events to outbound messages.
  • Inbound replies can appear even though they come through Mailgun routes rather than the event webhook endpoint.
  • Configure Webhook reports configured, partial, or error immediately. Verify Webhook checks the current Mailgun configuration directly; it does not wait for webhook traffic.
API key, domain, and auth problems
  • If setup fails immediately, confirm the Mailgun API key is valid and has access to the intended account/domain context.
  • If Check credentials fails, confirm the API Key can access the saved Domain.
  • If credentials pass but a flow cannot send, confirm Senders contains an email address and the email block uses it.
Webhook and verification problems
  • Select Verify Webhook. It succeeds only when the Drip Drop URL is registered for every event type selected by the current settings.
  • If an event type already has three URLs, review them before selecting Configure Webhook because Drip Drop keeps two existing URLs and replaces the oldest.
  • If signed delivery is rejected, confirm Enable Signed Webhooks is on, the correct Webhook Signing Key is saved, and the Mailgun timestamp is within five minutes of the server clock.
Tracking problems
  • If opens are missing, confirm Track Opens is enabled in Drip Drop, open tracking is enabled in Mailgun, and Mailgun’s tracking CNAME resolves.
  • If clicks are missing, confirm Track Clicks is enabled in Drip Drop, click tracking is enabled in Mailgun, and Mailgun’s tracking CNAME resolves.
Inbound routing problems
  • If replies never appear, verify the parse domain is configured correctly and that MX or DNS routing for that hostname points to Mailgun.
  • If the route exists but forwards to the wrong URL, update the forward action to the Drip Drop inbound endpoint.
  • If a reply is only threaded and no REPLY event appears, test again from a fresh Drip Drop send so the In-Reply-To tracking header can confirm the match.
  • See Integrations for the shared provider setup flow and provider management basics.
  • Compare SendGrid if you want a similar ESP-based workflow with different provider-side controls.
  • Compare Gmail or Outlook if you need a mailbox-style sender instead of a domain-based ESP.