Cold Email Sender Capacity
Email accounts × emails per account per day. Total send volume, sized.
Estimate your send capacity
INTERACTIVE · LIVE · DELIVERABILITY-AWAREIndustry best practice: 25-40 emails/account/day after a 2-3 week warmup. Going over 50/day with cold-from-scratch domains is a fast-track to spam. Multiple domains spread risk — if one gets flagged, others survive. Tools like Instantly and Smartlead let you operate unlimited accounts at a flat fee, which is why agencies use them.
Capacity assumes warmed mailboxes, valid SPF/DKIM/DMARC, and clean lists. Volume without infrastructure equals deliverability collapse — model conservatively.
What that capacity buys you
2% REPLY RATE · OUTBOUND TYPICALMore accounts is the lever, not more emails per account. Doubling daily volume per inbox doubles your spam-flag risk; doubling accounts at safe volume scales linearly without it. This is why Instantly and Smartlead lead the cold email space — they include unlimited accounts at every paid tier.
The cold email stack
FOUR REVIEWS · UNDER THIS CALCULATORInstantly
High-volume cold email with mailbox rotation and unified inbox. Built for scale.
Smartlead
Unlimited mailboxes, infinite warmup, agency-grade rotation. The volume play.
Lemlist
Personalization-first cold email. Image-and-video tokens, warm-up baked in.
Apollo.io
B2B data + sequencing in one. The default outbound seat for SDR teams under 50 reps.