Understanding Premium Warm-Up in Mission Inbox vs. Sequencer Warm-Up
Mission Inbox offers two warm-up methods to prepare your mailboxes for cold outreach. Understanding when to use which—and how they differ—is key to maintaining deliverability and scaling safely.
Mission Inbox offers two warm-up methods to prepare your mailboxes for cold outreach:
- Premium Warm-Up (powered by Mission Inbox)
- Sequencer Warm-Up (via your Sending Email Platform like Instantly, Smartlead, Lemlist, etc.)
💎 What is Premium Warm-Up?
Premium Warm-Up is Mission Inbox’s built-in warm-up engine that uses adaptive AI to gradually ramp up your mailbox’s sending activity safely and intelligently, outside your sequencer.
Unlike the basic warm-up tools in sending platforms (like Instantly or Smartlead), Premium Warm-Up runs through Mission Inbox’s private warm-up network and dynamically adjusts based on:
- 📈 Mailbox age
- 📉 Bounce and complaint rates
- ✉️ Reply activity
- 💡 Reputation signals
It includes:
- AI-powered warm-up scheduling
- Smart Gsuite/Office365 volume balancing (50/50 default)
- Real-time deliverability monitoring
- Pre-warmed infrastructure for inbox placement advantage
- Seamless warm-up credit management (billed automatically)
Why it matters: Premium Warm-Up helps protect your sender reputation from day one, giving you longer mailbox lifespan and stronger deliverability—especially at high volume.
🧠 What’s SEP Warm-Up?
SEP Warm-Up stands for Sending Email Platform Warm-Up. This is the built-in warm-up engine inside tools like Instantly, Smartlead, Lemlist, and Woodpecker. These tools warm up your inbox by sending and receiving low-volume emails across their shared inbox networks.
It's convenient but limited in optimization and insight, especially when scaling fast.
✅ Comparison at a Glance
| Feature | Premium Warm-Up | Sequencer Warm-Up (Smartlead, Instantly, etc.) |
|---|---|---|
| AI-Based Adaptive Ramp-Up | ✅ Yes | 🚫 No |
| Gmail/Outlook Split Control | ✅ 50/50 configurable | ❌ 90:10 or lower |
| Mailbox Rotation Optimization | ✅ Included | ❌ Manual |
| Real-Time Deliverability Logic | ✅ Based on bounce/reply rates | ❌ Static |
| Custom Warm-Up Scheduling | ✅ Yes | ✅ Limited |
| Credits Required | ✅ 9 credits/mailbox | ✅ Included in your SEP plan |
💡 When to Use Each One
🥇 Use Premium Warm-Up when:
- You want inbox rotation logic for longer-lasting mailboxes
- You need custom Gmail vs Outlook targeting
- You’re sending at high volume to Outlook inboxes and want placement protection
- You want to centralize warm-up within Mission Inbox
✅ Most high-volume senders at Mission Inbox use Premium Warm-Up for the first 45–60 days of every new mailbox if they're contacting Office365 recipients, but they can contact Gsuite + Others while they reach those days.
If you want to learn more about the warm up best practices and schedule refer to this article here
🧰 Use SEP Warm-Up when:
- You’re testing with just a few inboxes
- You prefer staying inside one tool (like Instantly or Lemlist)
- You’re running low volume and don’t need advanced deliverability optimization
⚠️ Warning: Never run both Premium and SEP warm-up at the same time. That will double your volume, risk throttling, and increase your chance of getting flagged.
🧮 How Premium Warm-Up Works (Behind the Scenes)
- Warm-up messages are sent using Mission Inbox’s private infrastructure
- Emails are opened, replied to, and clicked by trusted addresses in our warm-up network
- The system adapts based on:
- Mailbox age
- Bounce rate
- Complaint rate
- Reputation score
- Once a mailbox hits inbox health targets, warm-up will slow down or pause automatically
⚙️ How to Enable Premium Warm-Up
- Go to your Mailboxes tab
- Toggle Warm-Up ON next to any inbox
- Disable warm-up in your SEP (e.g., Instantly, Smartlead) to avoid overlap
- Mission Inbox will consume 9 credits/mailbox
💳 No pre-payment needed—credits are billed during your next renewal.
🤔 Still Not Sure Which to Use?
Use this rule of thumb:
- Premium Warm-Up = Best for deliverability-focused senders, TAMs with +30% Office365 recipients, enterprise (F1000 companies), larger volumes, and inbox longevity
- SEP Warm-Up = Fine for small-scale tests or minimal sending needs
🔁 Pro Tip: Rotate Every 60 Days
Regardless of warm-up type, rotate inboxes every 45–60 days.
It protects your domain’s reputation and ensures you always send from clean infrastructure.