Multi-Inbox Capacity Calculator

Calculate how many inboxes you need to hit a monthly send target safely.

How it works

How many inboxes to hit a monthly send target?

Enter monthly volume + safe daily per inbox → click Calculate capacity.

Or start from a real-life example

Results appear here after you click Calculate capacity.

Ready to send with MailShrine?

New accounts get free signup credits. Fix the copy, then send from MailShrine.