What Campaign Auto Warm Up Does
Campaign Auto Warm Up gradually increases your sending volume over a specified period, starting with lower volumes and progressively increasing each day. This helps build your sender reputation with email providers and improves your deliverability rates. The system automatically distributes emails across multiple days and inbox providers based on your selected warm-up approach.
This feature warms up your sending domain reputation, SendX's shared IP reputation, and your dedicated IP reputation (if you have one).
When and Why You Need This Feature
You should use Campaign Auto Warm Up when:
You're new to SendX and sending your first few campaigns
You've added a new sending domain to your account
You're migrating from another email platform with a large contact list
You haven't sent emails in several months and need to re-establish your reputation
You're scaling up send volumes significantly after a period of lower activity
Using this feature for your first few campaigns after any of these scenarios helps email providers recognize you as a legitimate sender, reducing the chance your emails land in spam folders.
Prerequisites Before Using Auto Warm Up
Before enabling Campaign Auto Warm Up, make sure you have:
Domain Authentication: Your SPF, DKIM, and DMARC records must be properly configured
Domain Verification: Your sending domain must be verified in SendX
A real recipient list: Auto Warm Up sends to actual subscribers, not test addresses
How to Enable Campaign Auto Warm Up
Step 1: Enable the Add-on in Settings
Click your profile icon in the navigation bar
Select Settings from the drop-down menu
Click Add-ons in the Settings menu
Find Campaign Auto Warm Up in the list
Toggle the switch to enable the feature
Note: This is a free add-on available on all SendX plans.
Step 2: Create or Select a Newsletter Campaign
Click the Campaigns drop-down in the navigation bar
Select Newsletters
Either create a new newsletter campaign or select an existing draft
Complete your campaign setup (design, subject line, preview text, etc.)
Important: Campaign Auto Warm Up is only available for Newsletter campaigns. It cannot be used with automated or trigger-based campaigns.
Step 3: Select Recipients and Access Scheduling
In your campaign workflow, proceed to the Edit Recipients step
Choose your target contact list or segment
Once recipients are selected, navigate to the Schedule step in the campaign workflow
Step 4: Enable Auto Warm Up Mode
In the Schedule page, look for the Auto Warm Up radio button option
Select Auto Warm Up Mode (instead of "Send Immediately" or "Schedule for Later")
Choose your preferred warm-up approach: Slow, Medium, or Fast
Click View Detailed Warm Up Plan to see how your emails will be distributed
The detailed plan shows:
Number of emails to be sent each day
Provider-level breakdown (which inbox providers receive emails on which days)
Total duration of the warm-up period
Choosing the Right Warm-Up Approach
The system offers three warm-up speeds. The breakdown of sends per day depends on your total recipient count.
Slow Conservative Approach (5 days)
Best for: Brand new accounts, newly verified domains, or if you haven't sent emails in 6+ months
Distributes your campaign over 5 days with the most gradual volume increase
Lowest risk of triggering spam filters
Medium Balanced Approach (4 days)
Best for: Accounts with some sending history or moderate domain reputation
Distributes your campaign over 4 days
Balanced between speed and safety
Fast Aggressive Approach (3 days)
Best for: Established accounts with good domain and IP reputation
Distributes your campaign over 3 days with faster volume ramps
Higher chance of improving deliverability quickly, but only if your reputation is already solid
Pro Tip: The better your current domain and IP reputation, the faster the warm-up type you can safely select. If you're unsure, start with the Slow or Medium approach for your first campaign.
Comparing Plans
You can switch between warm-up types before sending to compare the daily distribution:
Select a warm-up type from the drop-down menu (e.g., Medium Balanced Approach)
Click View Detailed Warm Up Plan to see the distribution
Change to a different warm-up type (e.g., Slow Conservative Approach)
Click View Detailed Warm Up Plan again to compare
This lets you see exactly how your sends will be scheduled before committing.
Sending Your Warm-Up Campaign
Once you've:
Selected your recipients
Chosen your warm-up approach
Reviewed the detailed warm-up plan
Click the Send button to schedule your warm-up campaign. The system will automatically execute the plan over the specified number of days.
Important Notes and Limitations
Billing and Credits
Campaign Auto Warm Up uses the same billing structure as regular campaigns
You'll be charged for the total number of emails sent, distributed across the warm-up period
Email credits are deducted as emails are sent each day
Campaign Management
You cannot edit or cancel a campaign once it enters sending state, even if it's midway through a multi-day warm-up
Multiple warm-up campaigns can run simultaneously if you have multiple newsletters scheduled
There is no minimum list size to use this feature, though it's most beneficial for larger lists (5,000+ contacts)
Feature Availability
Auto Warm Up is only available for Newsletter campaigns
It cannot be used with automated campaigns, trigger-based emails, or transactional messages
How This Differs from Spread Sending
If you're familiar with SendX's Spread Sending feature:
Spread Sending evenly distributes emails over a set time period
Auto Warm Up intelligently calculates distribution based on provider and reputation, starting small and progressively increasing
Auto Warm Up is specifically designed for reputation building, while Spread Sending is designed for even distribution.
Common Questions
Q: How many campaigns should I send using Auto Warm Up?
A: Use Auto Warm Up for your first few campaigns after setting up a new account, verifying a new domain, or returning after a long break. Once you've established a positive sending reputation (typically 3-5 campaigns), you can switch to normal sending.
Q: Will my subscribers notice anything different?
A: No. Recipients receive emails normally. They won't know your campaign was sent using Auto Warm Up.
Q: Can I use Auto Warm Up for every campaign?
A: You can, but it's not necessary once your reputation is established. Auto Warm Up is most valuable during the reputation-building phase.
Q: What happens if I need to make changes after clicking Send?
A: Once a campaign is in sending state, it cannot be edited or stopped. Review everything carefully before sending.
Q: Do I need to clean my list before using Auto Warm Up?
A: While not required, maintaining a clean list (removing invalid or inactive emails) always improves deliverability. However, the system does not require you to run list cleaning before enabling Auto Warm Up.
Q: Can I see which day of the warm-up is currently sending?
A: The detailed warm-up plan shows the full schedule before you send. Once the campaign is active, standard campaign reporting will show overall progress, but not which specific warm-up day is executing.
Need Help? If you're unsure which warm-up approach to choose or have questions about your domain reputation, contact SendX support for personalized guidance.