How often to send

Weekly, on a set day, is the place to start. Never let it fall below monthly. Then send most to the people who engage, and step up only when your own numbers say so.

The short version

• Start weekly, on the same day each week. Fortnightly suits a business that truly has less to say. Never less than monthly.
• Too little costs more than too much. In the best study there is, sending 4 emails a month instead of the best number lost about 32% of lifetime profit. Sending 10 lost about 16%.
• To stay in mind, send at least weekly, with room for an offer in between.
• Count everything one person gets: campaigns and sequences together. About one a day and four a week is a sensible cap for most businesses.
• Send most to the people who engage, less to the rest, and send the big offers to everyone.
• Step up on evidence, one notch at a time, when complaints stay under 0.1% and revenue per subscriber rises over 8 to 12 weeks.
• Judge it over a quarter, by revenue per subscriber and list size, never by one email's open rate.

More email: more clicks, and more goodbyes

MailerLite studied 12 billion emails from 42,000 of its own customers' accounts (published December 2025). Two things are true at once.

Per email, frequent senders do better: their readers expect them, so fewer leave each time. Per month, the totals move the other way. Worked out from those medians (sends a month × the rate per send):

Going from monthly to weekly more than doubles the clicks, for about half a point more loss a month. Daily loses about a tenth of the list every month, which only a business with a big, steady flow of sign-ups can carry. These are medians across different senders, so trust the shape more than the exact figures.

Too little costs more than too much

Zhang, Kumar and Cosguner modelled one retailer's email and its customers' buying over time (Journal of Marketing Research, 2017):

• The most profitable rhythm averaged 7 emails a month, from 5 to 14 depending on the customer.
• Sending 4 a month lost about 32% of lifetime profit. Sending 10 lost about 16%.
• The people who opened most weren't always the people who bought. Judge by sales, not opens.

It's one firm, and the authors say so. But the lesson matches everything else measured: most small businesses email too little, not too much. What sets the ceiling is how relevant the email is, not a number.

Why steady wins

• Mailbox providers ask for it. Google's sender guidelines say to send at a consistent rate and to avoid bursts.
• Readers expect it. A regular day is part of the promise your sign-up form made.
• A list left alone goes cold. Mailed rarely, then sent five emails in a week, it behaves like a cold list: more complaints, and more mail in spam.
• Most people aren't buying today. Regular email keeps you in mind for the day they are. For something bought rarely, a roof, a lawyer, a holiday, the email that counts is the one in the inbox the week the need arises.

Send most to the people who engage

Mailbox providers judge you by how people react. Mail sent to people who ignore it pulls down your inbox placement for everyone else.

• Send the regular rhythm to people who've clicked, replied or bought in recent months.
• Send less to the quiet ones, then win them back or stop. Carts, win-backs, events and receipts shows the win-back.
• Send the big offers to everyone.

Klaviyo's guidance from its own customers puts the split at about 70% of sends to people engaged in the last 30 to 60 days, 20% to those engaged in the last 90 to 180 days, and 10%, the major promotions, to everyone.

Even the most engaged can be worn out. A cap per person, counted across campaigns and sequences, protects them.

People leave over volume and relevance

In MarketingSherpa's 2017 survey of 2,400 consumers, people said they unsubscribed because of too many emails in general (26%), emails that weren't relevant to them (21%), too many from that one company (19%), and always being sold to (19%).

• Volume: send less to the people who want less. If you ask at sign-up what people want, "weekly tips" or "offers only", honour the answer in every campaign and sequence, or it's worse than not asking.
• Relevance: send each group what fits it: The right email for the right people.
• Always selling: mostly useful email, with offers in the mix.

An unsubscribe isn't the enemy. Someone who leaves cleanly would otherwise ignore you, or press "report spam", which costs far more. Watch complaints, not unsubscribes.

A starting rhythm for your kind of business

These are starting points. Move up while complaints stay low and revenue per subscriber rises. Move down when they don't.

And by goal:

Step up on evidence

1. 1

   Pick your starting rhythm from the tables above.

2. 2

   Keep it for 8 to 12 weeks.

3. 3

   Step up one notch when both hold: complaints stay under 0.1%, and revenue per subscriber rises.

4. 4

   Step back down when complaints near 0.1%, or when unsubscribes pass about 2% in a month.

To test a change fairly, raise the rhythm for a random part of the list, leave the rest as it was, and compare the two after 8 to 12 weeks: Test your emails.

Doing it here

• Every send goes out at a natural pace for each mailbox provider, so you decide how often to send, never how fast: Natural pace, and why it isn't warm-up.
• A sequence adds emails for one person at a time, so count it in their total: Sequences, one person at a time.
• An unsubscribe takes effect as soon as the person confirms it, or at once from their mail app's own Unsubscribe button: Unsubscribes, honoured everywhere.