Setup Instructions
Follow these steps to configure bounce handling for SMTP2GO:
Step 1: Get Your Webhook URL
- Go to QuillCRM → Settings → SMTP→ Bounce Handling
- Find the SMTP2GO section
- Copy the webhook URL provided


Your webhook URL will look like:> https://yoursite.com/wp-json/qc/v1/webhooks/bounce/smtp2go?key=your_security_key
Step 2: Configure SMTP2GO Dashboard
- Log in to your SMTP2GO Dashboard
- Navigate to Settings → Webhooks
- Click Add Webhook

- Configure the webhook:
| Field | Value |
|---|---|
| Webhook URL | Paste the webhook URL from Step 1 |
| Events | Select bounce-related events |
| Format | JSON |

- Click Save Changes
Bounce Events Handled
| SMTP2GO Event | Bounce Type | QuillCRM Action |
|---|---|---|
| hard_bounce | Hard | Mark as bounced immediately |
| soft_bounce | Soft | Track; convert after threshold |
| bounce | Auto-detected | Analyzed by SMTP code (5xx = hard, 4xx = soft) |
| blocked | Hard | Mark as bounced |
| reject | Hard | Mark as bounced |
SMTP Code Detection
SMTP2GO sends bounce codes that QuillCRM automatically interprets:
| Code Range | Type | Example Codes |
|---|---|---|
| 5xx | Hard Bounce | 550, 551, 552, 553, 554 |
| 4xx | Soft Bounce | 421, 422, 450, 451, 452 |






















