How many cold emails can you send per day from one mailbox?

There are two limits. The first is the cap your email provider sets on each mailbox, which you cannot exceed. The second is the volume at which your reputation stays healthy, which sits well below the first. The second one is the number to plan around.

What does a provider allow?

Google and Microsoft each publish a daily sending limit for their mailboxes, and the figures differ between free accounts and business accounts. They change over time, so read the current values in the Google Workspace and Microsoft 365 documentation before you plan around them. Both caps sit far above the volumes discussed below. A mailbox that reaches the provider cap is already sending at a rate no cold campaign should use.

Gmail and Yahoo also publish rules for bulk senders. They define a bulk sender by volume to their users, around 5,000 messages a day at the time of writing, and they apply that count to the sending domain. They ask for SPF, DKIM and DMARC records and for easy unsubscribing. They also set a spam complaint rate to stay under. Cold senders should meet the same standard well before they reach that volume.

What is a sensible daily volume per mailbox?

A common working range among cold email teams is about 30 to 50 messages a day per mailbox, with fewer on a new mailbox. This is practitioner convention. No provider publishes it, and we have no anymail dataset to quote for it. Treat 50 as a ceiling to approach slowly, and lower it when bounces rise.

In anymail the daily limit is set on each mailbox, and the workspace has a default you can change. The new mailbox form starts at 50. Follow-ups use the same limit as first emails, because they leave from the same mailbox.

How many emails can several mailboxes send?

Volume scales with the number of mailboxes. The table shows the arithmetic for a limit of 30 a day per mailbox.

Remember that every step of a sequence counts. If a sequence has a first email and three follow-ups, each prospect uses four sends over a couple of weeks. A daily total of 150 then reaches far fewer new prospects than 150 per day.

A domain reaches the same figures as the sum of its mailboxes. Ten mailboxes on one domain at 30 a day send 300 a day from that domain, and that is the volume providers see for its reputation. Spreading mailboxes across more than one domain spreads that risk, and each new domain needs its own SPF, DKIM and DMARC records.

How do you ramp up a new mailbox?

Raise the limit in small steps and watch the bounce rate at each one.

1. Start with a low daily limit, such as 10 or 15, for the first week.
2. Raise it by about 5 to 10 a day each week while bounces stay low and replies arrive.
3. Stop at the lower end of your range and hold it for a few weeks before you go higher.
4. Drop it again after any sudden rise in bounces, and check the list before you resume.

The schedule is an example. The principle behind it is that a mailbox with no sending history has no reputation yet, and a sudden jump looks different from a gradual rise.

What else shapes a safe send?

Pace and timing matter as much as the daily total. By default anymail spaces messages from one mailbox 4 to 15 minutes apart with a random element, and it sends inside a window of 9:00 to 17:00 on weekdays. You can change the window for each campaign. A burst of 50 emails in two minutes looks like a script.

Bounces matter more than volume. By default anymail pauses a campaign when more than 5% of sent emails bounce, once at least 20 have been sent, or when 3 emails in a row bounce. You can set the threshold between 1% and 20%. Both rules exist because a campaign often runs overnight, and the whole list can go out before anyone looks at a chart.

What are the limits of these numbers?

The range above is a starting point. A clean, verified list of well matched prospects tolerates more than a purchased list of unchecked addresses. A domain that has sent for a year behaves differently from one that is a week old. The only reliable guide is your own data: bounce rate and replies, plus any spam complaints your mailbox provider reports.

How does anymail enforce a limit?

In anymail each mailbox keeps its own daily limit and a campaign rotates through all the mailboxes you connect. Messages go out at randomised intervals, and the bounce shield pauses a campaign before a bad list does damage. More detail is on the deliverability page.