Workflow · Clean · Opening soon

Clean up a mailing list

Clean your mailing list from a Mailchimp export. Trim names, fix casing, remove duplicate emails, and label unsubscribed contacts.

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Someone typed

“clean our mailchimp audience contacts: trim first and last names, fix name casing, drop duplicate emails and any contact not subscribed, and show status Agrees, Duplicate, or Unsubscribed”

The agent read it as

clean our Mailchimp audience contacts: trim first and last names, fix name casing, drop duplicate emails and any contact not subscribed, and show status Agrees, Duplicate, or Unsubscribed, and keep them with status.

What the agent built

1 step, each one an ordinary Mammoth step you can open and change.

File

Mailchimp audience contacts

CSV export · 16 rows

Step

Clean and label contacts

Step 1

Result

Clean Mailchimp Contacts

16 rows · 4 flagged

Schedule

Runs when you say

Proposed

File
Mailchimp audience contacts
CSV export · 16 rows
Step
Clean and label contacts
Step 1
Result
Clean Mailchimp Contacts
16 rows · 4 flagged
Schedule
Runs when you say
Proposed

Checked on the sample files: every step ran, 16 rows came out.

Download Mailchimp audience contacts sample (16 rows)Mailchimp: Audience > All contacts > Export audience

What you get back

The result of that run, the rows to look at first.

Clean Mailchimp ContactsSample data16 rows

12 agrees2 duplicate2 unsubscribed

Email	First name	Last name	Status	Tags	Date added
amelia.hart@northstarstudio.com	Amelia	Hart	Duplicate	newsletter	2026-09-03
amelia.hart@northstarstudio.com	Amelia	Hart	Duplicate	newsletter	2026-10-18
hugo.martin@northstarstudio.com	Hugo	Martin	Unsubscribed	newsletter;vip	2026-10-06
daniel.ross@northstarstudio.com	Daniel	Ross	Unsubscribed	newsletter	2026-09-20
chloe.nguyen@northstarstudio.com	Chloe	Nguyen	Agrees	events	2026-09-14
karen.brooks@northstarstudio.com	Karen	Brooks	Agrees	vip	2026-10-22
grace.kim@northstarstudio.com	Grace	Kim	Agrees	events	2026-10-04
isla.ward@northstarstudio.com	Isla	Ward	Agrees	newsletter	2026-10-10
oliver.king@northstarstudio.com	Oliver	King	Agrees	vip	2026-11-07
leo.foster@northstarstudio.com	Leo	Foster	Agrees	newsletter	2026-10-27
jack.turner@northstarstudio.com	Jack	Turner	Agrees	events	2026-10-13
nina.owen@northstarstudio.com	Nina	Owen	Agrees	newsletter	2026-11-05

16 rows in the result · 12 shown, problems first. Sample data: illustrative figures, not business results.

How do you clean up a mailing list?

Export your Mailchimp audience contacts, then upload the file to Mammoth. It trims first and last names, fixes name casing, and marks each row as Agrees, Duplicate, or Unsubscribed while keeping the status with the contact.

How it works

How to use the Clean Mailchimp Contacts workflow

1Get early accessWe invite people in small batches, job by job. You'll land on this workflow, already built and checked on the sample files.
2Swap in your exportsUpload your own files as they come out of your tools. The agent checks the workflow on your rows.
3Change it in words, then turn it onSay what to change and see the new result before anything saves. Then choose when it runs.

Clean Mailchimp Contacts: questions

What file should I export from Mailchimp?

Export the audience contacts you want to clean, including the name and email fields you need for the rules. A spreadsheet-style export such as CSV works well.

What happens to contacts that do not match a rule?

Rows that do not match a rule stay in the file. They keep their original values unless a step changes them.

How do I change the cleanup rules?

Edit the steps in words, for example, trim spaces, fix casing, remove duplicates, or keep unsubscribed contacts with a status. Then run the workflow again on the exported file.