SMTP2GO

Connect SMTP2GO for reliable email delivery with built-in reporting and a generous free tier.

Prerequisites

• An SMTP2GO account
• An API key

Setup Steps

1. 1

   Create your API key

   In the SMTP2GO dashboard, go to Sending > API Keys and add a key. Under Permissions, grant the Emails permission (to send), the Webhooks permission (so GoodPostal can set up delivery tracking for you), and the API Keys permission (so GoodPostal can set up your unsubscribe link to appear inside your email's own footer design, see Where Your Unsubscribe Link Lands below). Optionally grant Statistics to show your monthly sending quota in GoodPostal. Then copy the key.
2. 2

   Add the provider in GoodPostal

   Go to Configure > Email Providers, click "Add Provider", select SMTP2GO, and paste your API key.
3. 3

   Test the connection

   GoodPostal will automatically test the API key. If the test fails, verify the key is correct and active.
4. 4

   Leave webhook setup switched on

   Set up webhooks automatically is checked by default. Leave it checked and GoodPostal registers the webhook on your SMTP2GO account, as described below.

API Key

API Key: api-xxxxxxxx...

Webhook Setup

You do not add the webhook in SMTP2GO yourself. GoodPostal registers it over the SMTP2GO API when you save the connection.

1. 1

   Leave automatic setup checked

   When you add SMTP2GO, the Set up webhooks automatically checkbox is already on. Leave it on and save the connection. Your API key needs the Webhooks permission for this to work.
2. 2

   GoodPostal configures SMTP2GO for you

   GoodPostal creates the webhook pointing at its own endpoint, subscribes it to every event listed below, and generates its own authentication token for it. There is nothing to copy or paste.
3. 3

   Re-run it whenever you need to

   Open Configure > Email Providers, select your SMTP2GO connection, and use Re-configure webhooks on the Webhook & Tracking card. Use this after you rotate an API key or if setup did not finish the first time.

Events GoodPostal Tracks

• Processed
• Delivered
• Open
• Click
• Bounce
• Spam
• Unsubscribe
• Resubscribe
• Reject

Signature Verification

SMTP2GO does not sign webhook payloads. Instead, GoodPostal registers the webhook with an Authorization: Bearer header holding a secret it generates, and checks that header on every incoming request. Events without the correct header are rejected with a 401 response.

Where Your Unsubscribe Link Lands

SMTP2GO can host your unsubscribe link, which saves you from needing a custom tracking domain. Which of three outcomes you get depends on your API key:

• Inside your footer design. The key has the API Keys permission, so GoodPostal places SMTP2GO's unsubscribe link exactly where you designed it. This is what you want.
• In a plain appended footer. The key lacks the API Keys permission but its Unsubscribes setting is already on, so SMTP2GO adds its own footer at the very bottom of each email.
• Hosted by GoodPostal. The key lacks the API Keys permission and its Unsubscribes setting is off, so GoodPostal cannot switch it on. GoodPostal then hosts the unsubscribe link itself, and a verified custom tracking domain is required before you can send any campaign. See Tracking Domain. To avoid this, grant the API Keys permission or turn Unsubscribes on for the key, then reconnect.

Troubleshooting

• Invalid API key - Ensure you are using an API key from SMTP2GO, not SMTP credentials
• Permission denied on connect - The API key needs the Emails and Webhooks permissions. Edit the key in SMTP2GO under Permissions and enable both.
• Unsubscribe link appears in a plain footer at the bottom - Grant the key the API Keys permission in SMTP2GO, then reconnect the provider in GoodPostal. The unsubscribe link will then appear inside your email's own footer design.
• GoodPostal says a tracking domain is required before you can send - Your API key lacks the API Keys permission and has Unsubscribes turned off. Fix either one in SMTP2GO and reconnect, or verify a custom tracking domain
• Webhook events not arriving - Open your SMTP2GO connection in Configure and check the Webhook & Tracking card. If it is not set up, use Re-configure webhooks
• Sending failed - Verify your sending domain is authenticated in SMTP2GO

See also: Webhook Configuration Guide