Your Sequence has been running for a month and the numbers say a call belongs before the last email. Now you can insert the stage right where it belongs. Recipients who haven't reached that point yet get it, and recipients who are already past it carry on as before.

The stages after the new one move down a number. Mixmax brings in-progress recipients up to date in the background, usually within a few minutes.

To add a stage at the end of a Sequence, use Add stage at the bottom of the stage list, the same as before.

Recipients have variable values defined when they are activated in a Sequence. If your new stage uses a variable they don't have, like {{phone}} for a call stage you just inserted, Mixmax tells you before you publish, and pauses those recipients at that stage until you fill it in.

This applies to any variable with no fallback. A variable with a fallback, like {{city | your area}}, always has something to send, so recipients will not pause. The same checks run if you add a new variable to an existing stage of a running Sequence.

While you edit, the Stage settings panel and the bar at the bottom of the editor tell you how many recipients have no value for the variable and will pause at this stage once you publish. Click Fill in to enter the values right away, or give the variable a fallback instead.

When you click Publish Changes, the dialog repeats the warning and gives you two choices:

The Recipients tab shows a banner with how many recipients are missing data a stage ahead of them needs. Each recipient's status says which variable is missing and which stage pauses them. When a recipient reaches that stage, their status changes to Paused: missing data with a Resolve… link.

Click Fill in variables in the banner to open the table filtered to the recipients who are missing something, or use the Missing data filter in the sidebar to see just those recipients.

You can edit the variables of anyone still in a Sequence at any time, not only when a value is missing. On the Recipients tab, click Edit recipient variables and choose Edit in a table or Update from a CSV.

In the table, each recipient is a row and each variable a column. Missing values are marked, and Only recipients missing data narrows the list to those. Type the values in, or copy a column from a spreadsheet and paste it: it fills down from the cell you're in. Click Save changes.

From a CSV, drop in a file with an Email column. Mixmax matches each row to a recipient by email and updates the other columns that match a variable name. Blank cells leave a value as it is, and nobody is added or removed.

Changes apply from each recipient's next stage. Anything already sent stays as it was. Only the person who added a recipient, or an admin, can edit their values.

Once a paused recipient has everything their stage needs, they resume on their own, and the banner clears. If you'd rather send the stage without the value, click Resolve… on the recipient and choose Resume anyway. That stage goes out with the variable blank, and later stages are still checked.

On the Insights tab, each stage's numbers stay with that stage. When you insert a stage, the stages after it move down a number and their results move with them.

Every time you insert a stage into a running Sequence, Insights starts a new iteration, so you can compare the Sequence before and after the change. Once a Sequence has more than one, an Include all iterations checkbox appears at the top of Insights:

The History tab lists every change to the Sequence, including each inserted stage and how many in-progress recipients it reached, plus any recipient paused for missing data, resumed, or whose variables you updated. The entry that started each iteration carries an Iteration badge. Click it to open Insights for just that iteration. Changes made through an AI assistant or the API are marked as such.

If you've connected Claude or another AI assistant to Mixmax through the Mixmax MCP, you can do all of this from chat. Your assistant can:

For example:

Your assistant never clears a value, and it can't resume someone with a value still blank. Use Resume anyway in Mixmax for that.

The dot and + only show in the new Sequence editor, so make sure Sequences Redesign is on in Mixmax Labs. They're hidden while you personalize a recipient, and on Sequences you can't edit. If you still don't see them, inserting stages may not be turned on for your workspace yet.

No. You can insert between two existing stages, or add to the end with Add stage.

Stages can't be removed while the Sequence has active recipients.

They were already past that point when you published. The stage after the new one had already been sent, or skipped, for them. Their row on the Recipients tab says so.

A variable written plainly in a stage, like {{phone}}, with no fallback and outside any Liquid if block. Variables with a fallback, {{first name}} and {{name}} when the recipient has a name, and variables Mixmax fills in itself, like the unsubscribe link, never pause anyone. A task's title is never checked, only its description.

Filling in their values doesn't resume them. Resume them when you're ready, and if a value is still missing, they pause again at that stage.

Inserted stages and the results of recipients who skipped them show there too, but you can't insert a stage from it. A recipient paused for missing data shows as Paused without the reason. Switch to the new editor to see why and to fill in the values.