Sending volume
What Is Sender Rotation in Cold Email?
Learn how sender rotation distributes campaign messages across eligible mailboxes and where its operational limits are.
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Mailbox Capacity Calculator
Estimate daily capacity and how many mailboxes a campaign needs.
Days between steps
Maximum daily sending capacity
150emails / day
First emails 2,000 Follow-ups 3,705 · 65%
Total sequence sends
5,705
Mailboxes to reach all contacts in one day
67
Weekly send capacity
750
New contacts per week
262
How it's calculated
- Daily capacity
- sendingMailboxes × dailySendTargetPerMailbox
- Total sends
- contacts + Σ remaining contacts after stop/reply rate, per follow-up step
- Sending days
- ceil(total sends ÷ daily capacity)
No sending limit is universally safe. Provider rules, mailbox age, domain authentication, engagement, complaint rate, and account reputation change practical capacity.
Planning 2,000 contacts across 5 mailboxes? Use MailQV to rotate senders, schedule follow-ups, and monitor replies.
Start freeSizing your mailbox pool
Daily capacity is simply mailboxes × the daily target per mailbox. Follow-ups share the same capacity as first emails, so a 3-step sequence needs close to three times the sends of the first touch — less as replies and opt-outs stop contacts.
New mailboxes should start low and ramp up. MailQV Safe Mode ramps each mailbox toward its target automatically and never exceeds your limit.
Resources
Related guides
Quick reads to help you plan audiences, sending volume, sequences and measurement before launch.
Sending volume
How Many Cold Emails Can You Send Per Day?
Calculate a practical cold email daily volume from mailbox capacity, list quality and provider constraints—not a universal magic number.
Sending volume
How Many Mailboxes Do You Need for Cold Email?
Estimate mailbox requirements with daily capacity, sequence demand, send windows and a buffer for interruptions.
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