How Does Load Balancing Work?
Understanding how Superkabe distributes sending load across your mailboxes to maximize deliverability
Quick Answer
Superkabe's load balancing analyzes how your mailboxes are distributed across campaigns. It identifies overloaded, optimal, and underutilized mailboxes, then provides actionable suggestions to rebalance your infrastructure for better deliverability.
Access it from Dashboard → Load Balancing.
What Is Mailbox Load Balancing?
When you run multiple campaigns, each campaign uses one or more mailboxes to send emails. If too many campaigns share the same mailbox, that mailbox becomes overloaded — increasing its bounce risk and hurting sender reputation. Conversely, underutilized mailboxes represent wasted capacity.
Superkabe continuously monitors your mailbox-to-campaign ratio and flags imbalances before they cause deliverability problems.
How Are Mailboxes Categorized?
Overloaded
The mailbox is assigned to too many campaigns. This increases sending volume beyond safe thresholds and raises bounce risk.
Action needed: Move this mailbox out of some campaigns or add additional mailboxes to share the load.
Optimal
The mailbox has a healthy number of campaign assignments. Sending volume is within safe limits. No action required.
Underutilized
The mailbox is assigned to very few or zero campaigns. It could be added to campaigns that need more sending capacity.
What Metrics Does Superkabe Show?
Total mailboxes and campaigns in your organization
How many mailboxes are overloaded, optimal, or underutilized
Average number of campaigns per mailbox across your org
How Do Optimization Suggestions Work?
Superkabe generates prioritized suggestions based on your current mailbox distribution. Each suggestion includes a priority level and a recommended action:
Add Mailbox
A campaign needs more mailboxes to handle its sending volume safely. Click Apply to add a suggested mailbox instantly.
Remove Mailbox
A campaign has too many mailboxes relative to its volume. Click Apply to remove the excess mailbox from the campaign.
Move Mailbox
A mailbox would perform better in a different campaign. This suggestion is informational — review and adjust manually in your sending platform.
When Should I Rebalance?
Rebalance When:
- •You see overloaded mailboxes (red) in the report
- •After adding or removing campaigns
- •After mailboxes are paused or enter recovery
- •When bounce rates increase unexpectedly
Health Warnings
If Superkabe detects infrastructure issues that affect load balancing, a Health Warnings section appears at the top of the report. These warnings indicate:
- • Campaigns with zero healthy mailboxes
- • Mailboxes in recovery that shouldn't receive new campaigns
- • Domains with unhealthy mailbox ratios