Optimal email sends per week before unsubscribe rate spikes.
Inputs
Avg $/recipient at current pace
% of list unsub per send
Current performance
Weekly revenue
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Annual revenue
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Annual unsubs
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Frequency scenarios (1 year forward)
Sends / Week
List Size EOY
Annual Revenue
vs Current
About this calculator
Email send frequency is one of the few marketing decisions where doing more produces less — past a point. Each additional weekly send adds short-term revenue but accelerates list erosion through unsubs. The math gets ugly fast: 5 sends/week at 0.4% unsub each adds up to ~80% list loss over a year if unchecked.
This calculator models the trade-off explicitly. At your current revenue-per-send and unsub rate, what does each frequency level produce annually? Below ~2 sends/week, you\'re leaving revenue on the table. Above ~4 sends/week, list erosion outpaces revenue gains within 12 months.
The diagnostic insight is that revenue-per-send tends to decline as frequency rises. The first weekly send hits engaged customers; the fourth hits people who already saw the previous three and are getting numb to the offer. Track RPS over time. A 30% RPS decline as you scaled from 2 to 4 sends/week is signal that you\'re past the sweet spot.
The advanced play is segmentation: send more frequently to engaged subscribers (opens/clicks in last 30 days) and less frequently to disengaged. This concentrates volume on people who want it, protects sender reputation, and stretches the optimal frequency for engaged segments to 4-5/week without damage. Pair this with the Email List Decay Calculator and the Email Revenue Calculator for the full picture.
Frequently asked questions
What's a healthy send frequency?
2-3 sends per week is the sweet spot for most DTC ecommerce. Below 1/week your list goes cold (engagement drops, deliverability suffers). Above 4/week unsubscribe rate spikes, especially on the first 30 days. Promotional periods (BFCM, holidays) can sustain 5-7/week without damage if cadence returns to normal after.
How does over-mailing damage long-term revenue?
Two ways. First, list shrinkage: each extra send beyond optimal frequency unsubs ~0.3-0.5% of recipients. Compound that over a year and you've lost 15-25% of your list. Second, deliverability degradation: low engagement signals (low opens, low clicks) tell ESPs your list is uninterested, which lowers inbox placement for ALL future sends.
Should I segment by engagement?
Yes — biggest deliverability win available. Send 3-4×/week to engaged segments (opened/clicked in last 30 days) and 1×/week to low-engagement segments. Or sunset segments that haven't engaged in 90+ days. This concentrates volume on people who want it and protects sender reputation.
What's revenue per send?
Total revenue from a campaign divided by recipients. Healthy ecommerce campaigns produce $0.10-0.50 RPS. Below $0.05 RPS suggests either misaligned offers or list fatigue. Track over time — a declining RPS trend is the earliest warning of over-mailing.
How fast does an over-mailed list recover?
60-90 days of disciplined frequency reduction. Pause sending to disengaged subs entirely, focus campaigns on engaged segments, and let the list "rest." Engagement metrics rebuild slowly — there's no shortcut.