How to Set Up Mailgun Inbound Email for Sparkforge

Inbound email lets Sparkforge receive replies, route them into conversations, and trigger workflows. Mailgun handles the routing. The setup is straightforward, but one rule sinks more configurations than any other: a domain can only point its MX records to one provider at a time.

What inbound email does

With Mailgun configured, replies to messages sent from Sparkforge can be:

• Forwarded to another email address.
• Posted to a webhook.
• Logged and processed inside a workflow.

Root domain vs subdomain — read this first

A domain has exactly one set of MX records. That means you cannot use Mailgun and Google Workspace (or Outlook 365) to receive email on the same domain at the same time.

Why root domain plus existing inbox fails

If yourdomain.com is already on Google Workspace, adding Mailgun MX records alongside the existing ones produces unpredictable delivery. Email is not designed to split inbound across providers — pick one.

Recommended setup: use a subdomain

Point a subdomain like mg.yourdomain.com at Mailgun and leave the root domain on your normal email provider. You get:

• Outbound and inbound through Mailgun on the subdomain.
• Your normal inbox untouched on the root domain.
• No MX conflicts.

Setup steps

1. Configure Mailgun

Set up your Mailgun account with the subdomain (for example mg.agency.com). One Mailgun account can host multiple sub-account subdomains — for example client1.agency.com, client2.agency.com. Each sub-account gets its own subdomain so replies route to the right place.

If your client uses their own domain that already has email service, set up a subdomain on their domain for Mailgun rather than the root.

2. Map each Mailgun domain to one sub-account

Sparkforge uses the Mailgun domain to decide which sub-account receives the reply. If the same domain is shared across multiple sub-accounts, Sparkforge cannot route correctly when a lead emails the reply-to address directly.

Verify the mapping at Agency View > Settings > Email Services > Location Settings. Confirm the domain shows up under exactly one sub-account.

3. Add MX records for the Mailgun subdomain

At your DNS provider, add two MX records on the subdomain:

• mxa.mailgun.org with priority 10
• mxb.mailgun.org with priority 10

4. Verify all DNS records in Mailgun

In Mailgun, open Sending > Domain Settings, pick the domain, click DNS records, then Verify DNS settings. All five (SPF, DKIM, MX x2, tracking) need green checks.

Common pitfalls

• Sharing one Mailgun domain across multiple sub-accounts — replies become un-routable. One domain, one sub-account.
• Adding Mailgun MX records to a root domain that already has Google or Outlook MX records — delivery becomes unreliable. Move to a subdomain.
• Forgetting to verify DNS in Mailgun — Mailgun does not consider a domain active until verification passes.