How Many Mailboxes Do You Need?
Enter your target replies and meetings. We calculate the exact number of mailboxes, domains, and daily sends you need.
How it works
Enter your goals
How many replies or meetings per month do you want?
We calculate backwards from your goals
Using industry conversion rates: sends to opens to replies to meetings.
Get your exact infrastructure plan
Number of mailboxes, domains, daily sends per mailbox, and estimated costs.
Why this matters
Most cold email campaigns fail because people send too many emails from too few mailboxes. Gmail and Outlook allow roughly 15 emails per day per mailbox for safe cold outreach. Azure SMTP caps at around 2 per day. Getting the math wrong means spam folders, blacklists, and burned domains.
Set up your infrastructure in minutes
SendKit gives you unlimited mailboxes on dedicated IPs with automated warmup. Connect, warm up, and start sending.
Unlimited mailboxes
Connect as many mailboxes as you need on every plan
Dedicated IPs
Your own IP addresses. Your sender reputation stays yours.
Automated warmup
Every new mailbox gets warmed up automatically
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Got questions? We've got answers.
For safe cold outreach: Gmail and Google Workspace allow roughly 15-20 emails per day. Outlook/Microsoft 365 is similar at 15-20. Azure SMTP relay is much more restrictive at around 2 per day. Exceeding these limits triggers spam filters.
Ready to hit primary?
Set up SendKit's isolated infrastructure and start sending in under 15 minutes.
Dedicated IPs on every plan. Cancel anytime.