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:

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.