How automations work

An automation sends email to one contact at a time, triggered by something that happened to that contact. By the end of this page you will know how an automation differs from a campaign, what the pieces are called, and which of the two to reach for.

A campaign versus an automation#

A campaign is a single send. You write it, you pick a list or a segment, and it goes out to everyone in that audience at roughly the same moment. Everyone who receives it receives it on the same day. When the send finishes, the campaign is done. That is the model described in Create a campaign.

An automation is a set of instructions that runs per contact. Nothing happens on a schedule you set in advance. Instead the automation waits, and when a contact does something that matches the trigger, that one contact starts moving through the steps. Someone who subscribes today gets the first email today. Someone who subscribes in March gets the same first email in March. Two contacts can be at completely different points in the same automation at the same time.

That difference has a practical consequence. A campaign is measured once: one open rate, one click rate, one send date. An automation keeps producing sends for as long as it is active, and its numbers accumulate over weeks.

The building blocks#

Every automation is built from three kinds of piece.

The trigger

The trigger is the event that puts a contact into the automation. It is the only part that decides who enters and when. Common triggers are a contact joining a list, a field on the contact changing value, a date stored on the contact arriving, and something the contact did with a previous email.

An automation has one trigger. If you want the same emails to go to two different groups of people who qualify in two different ways, that is usually two automations, or one automation with a broader trigger and a condition that filters early.

Actions

An action is something the automation does when a contact reaches that step. The two useful families are sending an email and changing the contact.

Sending an email is what most steps do. The email is written the same way a campaign email is written, and the same personalization applies, so Personalization tags works exactly as it does elsewhere.

Changing the contact means writing to a field, adding the contact to another list, or removing them from one. These steps send nothing, but they are what lets a later step, or a different automation, behave differently for this person. Setting a field to record that someone finished the welcome sequence is a small step that saves a lot of trouble later.

Delays

A delay holds the contact at that point for a set amount of time before the next step runs. Delays are what turn a pile of emails into a sequence. Without a delay between two email steps, both emails go out in the same minute.

Delays are measured from the moment the contact reaches the delay step, not from when they entered the automation. Three steps with two-day delays between them means the third email arrives on day four, not day two. This is worth checking on paper before you activate anything. Triggers and timing goes through the arithmetic in more detail.

Conditions

Some automations also branch. A condition looks at the contact at that moment and sends them down one of two paths, based on something like whether they opened the previous email or whether a field has a particular value. Branching is useful, and it is also the fastest way to make an automation hard to reason about. Two branches is usually enough.

When to use which#

Reach for a campaign when the content is tied to a date rather than to a person. A product announcement, a newsletter, a sale that ends on Friday, a webinar invitation: everyone should get these at the same time, and the content stops making sense a week later. A campaign is less work to build and easier to check before it goes out.

Reach for an automation when the content is tied to something the contact did, and when the right time to send it depends on them. A welcome message makes sense in the hour after someone signs up and makes no sense three weeks later. Onboarding education, a course delivered over days, a nudge to people who have gone quiet, a message on an anniversary date: these all belong in an automation.

What automations cost you#

Emails sent by an automation count against your monthly sending allowance in exactly the same way campaign emails do. There is no separate allowance for automated sends. An automation attached to a list that grows steadily will consume more allowance each month without you changing anything, so keep an eye on it after you activate it.

Automations also inherit your deliverability, and they can quietly damage it. A sequence that keeps mailing people who never open is the same problem described in Deliverability overview, except it runs unattended. Build an exit into any sequence that keeps sending to unresponsive contacts.