Limits and thresholds

Every limit Issue Mint enforces is on this page, with the figure the software actually uses and what it applies to. Most publishers never meet one, each of the limits that can stop something warns you well before it does, and a new account has all of them already, because sending works from the day you register.

Plans, the trial and your data

Your plan is worked out from the number of active subscribers across every newsletter on the account, and it moves up and down on its own as that number changes.

Limit	Figure	Applies to
Free trial	14 days	Every new account, no card
Starter plan	1,000 active subscribers	Accounts on Starter
Growth plan	5,000 active subscribers	Accounts on Growth
Pro plan	15,000 active subscribers	Accounts on Pro
Scale plan	40,000 active subscribers	Accounts on Scale
Summit plan	100,000 active subscribers	Accounts on Summit
Days over the limit before an upgrade	7 days	Paid accounts
Data kept after a cancellation	60 days	Cancelled accounts

A list more than 115 per cent of the way past its plan limit moves up the same night rather than waiting out those days, because that is a move rather than a spike. A downgrade waits until the end of the period you have already paid for.

Hosted sending

Hosted sending has two boundaries, a monthly email allowance and a subscriber cap. Each one warns before you reach it and then gives you a grace period, and the figures for both are below.

Limit	Figure	Applies to
Monthly email allowance, floor	50,000 emails	Hosted sending
Monthly email allowance, per subscriber	15 emails	Hosted sending
Allowance warning	80 per cent of the allowance	Hosted sending
Grace after the allowance	30 days	Hosted sending
Subscriber cap	15,000 active subscribers	Hosted sending
Cap warning	12,000 active subscribers	Hosted sending
Grace after the cap	30 days	Hosted sending

The allowance is the larger of the two figures at the top, so a small list is never touched by it. What stops when a grace period runs out is the sending and nothing else, which the page on sending limits covers in full.

Trial and warm-up ceilings

A new account has a daily sending ceiling that grows, and a trial account has two fixed ones on top of it.

Limit	Figure	Applies to
Emails in total	2,000	Trial accounts
Recipients per issue	500	Trial accounts
Rows per import	500	Trial accounts
Daily ceiling on day one	1,000 emails	Hosted sending
First send that waits for review	above 2,000 recipients	Hosted sending

The daily ceiling doubles every clean week, meaning one with no bounce or complaint problem, up to your plan limit. That ramp is ordinary sender warm-up. Subscribing lifts the trial figures immediately, and a first send above the review threshold is held once and never again.

Bounces, complaints and failures

Hosted sending is warned and then paused at the rates below, which are the numbers Amazon acts on, reached first.

Limit	Figure	Applies to
Complaint rate warning	0.05 per cent	Hosted sending
Complaint rate pause	0.1 per cent	Hosted sending
Hard bounce rate warning	2 per cent	Hosted sending
Hard bounce rate pause	5 per cent	Hosted sending
Delivered messages before a rate counts	500	Hosted sending
Failures that flag an issue	5 per cent of recipients	Every newsletter

Two absolute triggers sit underneath the floor, because a rate on a small list says nothing: three complaints on a single issue pauses sending at any size, and so does a quarter of a send bouncing once it has reached 100 recipients. A rate is measured on the issue whose bounce and complaint events came in, or across the account’s last day.

Imports and signups

An import is checked before any address becomes mailable, and two thresholds decide whether that check involves a person.

Limit	Figure	Applies to
Largest CSV file	20 MB	Every account
Rows before an import is held	above 5,000	Hosted sending
Growth that holds an import	more than double your list	Hosted sending
Refused addresses kept	180 days from the last sighting	Every account
Confirmation reminder sent after	3 days	Newsletters using double opt-in
Oldest signup still worth a reminder	14 days	Newsletters using double opt-in

A held import keeps every address it read, on the list and unmailable, until somebody here releases it. The reminder is sent once per signup and never again.

How fast an issue goes out

Sending runs in batches, at a rate set by whoever owns the sending account.

Limit	Figure	Applies to
Recipients per batch	200	Every newsletter
Hosted send rate	12 a second	Hosted sending
Starting rate on your own provider	10 a second	Your own SES or SMTP

On your own Amazon SES account Issue Mint reads the real quota and uses that instead of the starting figure. A batch is attempted three times before it is recorded as failed, and a failure is counted per recipient rather than per batch.

What each list, feed and report shows

The figures below are sizes and windows behind the screens rather than limits anything can breach.

Limit	Figure	Applies to
Subscribers per page	50	The dashboard list
Issues per page	25	The dashboard and your archive
Issues in your RSS feed	50	Every newsletter website
Hourly click curve	48 hours	Every issue report
Issues behind the engagement segments	5	Subscriber analytics

Sponsorship, the extension and pasted links

The sponsorship calendar, the browser extension and the look-up behind a pasted URL each have figures worth knowing.

Limit	Figure	Applies to
Issue dates on the calendar	26	Newsletters with a schedule
How long an enquiry holds its dates	7 days	Reserved slots
Pairing code length	8 characters	The Chrome extension
Pairing code lifetime	10 minutes	The Chrome extension
Issues offered in the popup	20 per newsletter	The Chrome extension
Time spent reading a pasted URL	5 seconds	Every account
Most read from a pasted URL	1 MB	Every account
Redirects followed	3	Every account

The calendar horizon is refreshed weekly, so it always runs about half a year ahead for a weekly newsletter. What you can put in those dates is covered in what you sell to sponsors.