Will Renta resubscribe contacts who unsubscribed?

Not unless you map **Subscription status**. Without it, a contact that is already in the audience keeps its status, and **Status for new contacts** applies only to contacts Renta adds. A mapped status overwrites the stored one, including for contacts who unsubscribed.

Does Renta create merge fields or audiences?

No. Create the audience and its merge fields in Mailchimp first. Renta reads them when you open the pipeline settings and writes only to fields that already exist.

Why was a tag row rejected?

A **Tags** pipeline adds tags to contacts that are already in the audience. When the email address is not there, the row is rejected with a note in the run log. Add the contact with an **Audience members** pipeline first.

Can one pipeline write to several audiences?

No. A pipeline writes to the audience selected in its settings. To fill two audiences, create a pipeline for each.

What happens to an archived contact when its row comes back?

Mailchimp keeps an archived contact with its merge fields and tags. When the row appears in the data model again, the next run brings the contact back into the audience.

When do I need to re-authorize the connection?

When the access Renta was granted stops working, for example after the app is removed from your Mailchimp account. Open the destination, click **Re-authorize**, and log in again. The connection keeps its name, and every pipeline built on it keeps running.

Mailchimp

Renta sends rows from your data warehouse to a Mailchimp audience as contacts with their merge fields, or as tags on contacts that are already in the audience.

A pipeline writes to one audience and finds contacts by email address. A contact that is already in the audience keeps its subscription status, unless you map the status yourself.

Authentication

Renta connects to Mailchimp with OAuth. You log in to your Mailchimp account and allow access, and Renta works with every audience of that account.

Renta reads audiences and merge fields to fill the pipeline settings and writes the contacts and tags that pipelines deliver.

Your credentials are encrypted, and you can revoke the access at any time in your Mailchimp account.

Connect Mailchimp destination

Go to the CatalogStep 1

Navigate to the Connections > Catalog section in the left sidebar and open the Destinations tab.
Open the Email marketing category and click the Mailchimp card.

Start the authorizationStep 2

Click Log in to your Mailchimp account. Mailchimp opens in the same tab.

Log in with the account that owns the audiences you want to fill. If Mailchimp asks for a verification code, enter it. On the next screen, click Allow. Mailchimp returns you to Renta.

Name the connection and saveStep 4

Renta confirms the granted access and shows the connected account. Finish the setup:

Destination name.
Renta fills it with the name of your Mailchimp account. Change it to any name you like. The name is used only in the Renta interface.

Click Save to finish.

Destination createdStep 5

The new destination appears in the Destinations list with the Active status. You can now use it in Reverse ETL pipelines.

Prepare a data model

A Reverse ETL pipeline reads from a data model: a SQL query saved in the Data models section that decides which warehouse rows to sync and what each row holds. Build it before the pipeline, because the mapping dropdowns are filled from its columns.

Include the contact's email address and a column with a stable identifier of the row, such as a customer id. The identifier becomes the unique key of the model and lets Renta tell a changed row from a new one.

-- Contacts prepared for Mailchimp. The query returns rows only, no table is created.
WITH demo_contacts AS (
  SELECT
    'mc-demo-0001'               AS customer_id,
    'james.miller@example.com'   AS email,
    'James'                      AS first_name,
    'Miller'                     AS last_name,
    'Northwind Traders'          AS company,
    'pro'                        AS plan
  UNION ALL SELECT 'mc-demo-0002','olivia.johnson@example.com','Olivia','Johnson','Contoso Retail','free'
  UNION ALL SELECT 'mc-demo-0003','william.davis@example.com','William','Davis','Fabrikam Inc','enterprise'
)
SELECT * FROM demo_contacts

Create the data model

Write the queryStep 1

In the left sidebar, open Data models and click New model. Then:

Source.
Choose the warehouse connection the query runs against.
Write your model query.
Paste your SQL. Keep SQL query as the query type.
Run preview.
Check the rows and column names. Click Next step when the result looks right.

Choose the scopeStep 2

Pick Reverse ETL only for a model that feeds pipelines. Choose one of the AI agents options instead if the same model should also answer agent questions.

Confirm the columns and pick the keyStep 3

Review the columns Renta read from the query and mark the one that identifies a row, such as customer_id in the example.

Name the modelStep 4

Give the model a name and a short description, then click Create model. The name is what you pick from the Data model dropdown when you build the pipeline.

Model createdStep 5

The model appears in the list with the Reverse ETL scope and is ready to use in a pipeline.

Create a Mailchimp pipeline

The destination and the data model have to exist before you start.

Select your warehouseStep 1

In the left sidebar, click New pipeline. On the Source step, switch the toggle to Reverse ETL, pick your data warehouse, such as Google BigQuery, and click Next step.

Select the warehouse connectionStep 2

Choose the warehouse connection that holds your data models and click Next step.

Select Mailchimp as the destinationStep 3

On the Destination step, select Mailchimp under Already connected and click Next step.

Select the destination connectionStep 4

Choose the Mailchimp connection you created earlier. The card shows the account name and its data center. Click Next step.

Pipeline configuration

On the final step, choose the data behind the pipeline, the audience it fills, and what Renta sends there.

Data model and audience

Point the pipeline at the data and at the audience that receives it. The fields you can map below depend on both choices.

Data model.
Choose the model to sync. The columns available for mapping come from it.
Audience.
Choose the Mailchimp audience Renta writes to. Renta reads the list from your account and shows the audience ID and the number of subscribed contacts next to each name.

What to send

Choose whether the rows become contacts or tags.

Option	Description
Audience members	Adds contacts to the audience and keeps their fields up to date. One row is one contact.
Tags	Adds a tag to contacts that are already in the audience. One row is one tag on one contact.

Status for new contacts

This setting appears for Audience members only. It sets the subscription status of contacts that Renta adds to the audience.

Status	Description
Subscribed	New contacts can receive your campaigns right away. This is the default.
Pending	Mailchimp emails each new contact a confirmation link. The contact is subscribed after they confirm.
Unsubscribed	New contacts are stored in the audience and receive no campaigns.
Transactional	New contacts receive transactional emails only.

A contact that is already in the audience keeps its status. Renta changes it only when you map the Subscription status field.

When a source row is deleted

Set what happens in Mailchimp when a row disappears from the data model. Renta never deletes a contact permanently.

Option	Available for	Description
Ignore	Audience members, Tags	The contact and its tags stay as they are. This is the default.
Unsubscribe	Audience members	Sets the contact to unsubscribed. The contact and its data stay in the audience. Contacts that are already unsubscribed, cleaned, archived, or missing are left as they are.
Archive	Audience members	Archives the contact. Mailchimp keeps its data, and the contact returns to the audience when its row comes back.
Remove tag	Tags	Removes the tag from the contact. The contact stays in the audience.

Field mapping

Connect the columns of your data model to Mailchimp fields. Email address is always the first row and cannot be removed: it is how Mailchimp finds the contact.

Mapping type	Description
Standard	Takes the value from a data model column.
Static	Writes the same fixed value into every contact.
Variable	Writes a value from the sync itself, such as the data model name or the time the run started.

The right-hand dropdown lists the contact fields of Mailchimp followed by the merge fields of the selected audience. Under each field, Renta shows the value it expects. A field that is already mapped is greyed out.

Mailchimp field	What to send
Email address	The contact's email. Renta lowercases it. A row without an email is rejected.
Subscription status	One of subscribed, unsubscribed, cleaned, pending, or transactional. Any other value rejects the row.
Language	A language code, such as en or fr.
VIP	true or false. The values 1, 0, yes, and no are accepted too.
Email format	html or text.
Tags	A list of tag names, a JSON array, or a comma-separated string. The tags are added to the contact, existing tags stay.
Text, phone, ZIP, URL, and image merge fields	Any text value.
Number merge fields	A number.
Date merge fields	A date, such as 2024-01-15. Free text is not accepted.
Birthday merge fields	A date, or a month and day written month first, such as 12/31. Renta writes it in the format the field uses in Mailchimp.
Dropdown and radio merge fields	One of the choices defined in Mailchimp. Letter case does not matter.
Address merge fields	One row per part: street address, city, state or province, postal code, address line 2, and country.

A value that does not fit the field type is skipped for that row, and the rest of the row is still delivered. Mailchimp keeps the value it had.

An address needs the street address, city, state or province, and postal code. When one of them is empty in a row, Renta leaves the whole address out of that row.

A mapped Subscription status overwrites the status of existing contacts too, including contacts who unsubscribed. Map it only when your warehouse is the record of your contacts' consent. To set the status of new contacts only, use Status for new contacts instead.

Null values

Each mapping row has its own rule for empty source values. Open it with the gear icon next to the row.

Option	Description
Don’t sync null values	Skips the field when the source column is empty, so Mailchimp keeps its current value. This is the default.
Always sync	Clears the Mailchimp field when the source column is empty. Use it when the warehouse is the single source of truth for that field.

Always sync clears merge fields and Language. VIP, Email format, Tags, and Subscription status have no empty state, so an empty value in them is always skipped.

Schedule

Choose how often the pipeline runs.

Schedule type	Description
Manual	The pipeline runs only when triggered manually through the interface or via API.
Daily	The pipeline runs once a day at the specified update time.
Interval	The pipeline runs at specified time intervals.
Cron Expression	The pipeline runs on a schedule defined by a cron expression.

For Daily schedules, set the Update time (the exact time each run starts), then click Create pipeline.

Renta also supports API triggers and integration with external orchestrators such as Apache Airflow, Dagster, and Prefect. See the full scheduling documentation for details.

The new pipeline appears in the Pipelines section under the Reverse ETL tab, where you can track its runs and progress.

Sync strategy

Renta syncs incrementally. A run compares the data model against the state the previous run recorded and sends only what changed. The first run has nothing to compare against and delivers every row.

Row state	Audience members	Tags
New	Adds the contact with the status for new contacts, or updates the contact that has this email address.	Adds the tag to the contact.
Changed	Writes the mapped fields again with the new values. Fields outside the mapping stay as they are.	Adds the tag from the new values. The tag from the previous values stays on the contact.
Unchanged	Sends nothing.	Sends nothing.
Deleted	Follows the deletion policy: ignore, unsubscribe, or archive.	Follows the deletion policy: ignore or remove the tag.

Limits

One audience per pipeline.
A pipeline writes to the audience selected in its settings. Create a pipeline for each audience you fill.
Email addresses must be unique in the model.
When several rows of one run share an email address, the last row is delivered and the others are rejected.
A rejected row does not stop the others.
Mailchimp answers per contact, so a row it refuses is rejected on its own and the rest of the batch still lands. The reasons appear in the run log.
A run stops when rejections pile up.
Renta halts the run when more than 30% of a batch, or more than 10% of the rows delivered so far, come back rejected. Contacts already written stay in Mailchimp.
Merge fields are not created for you.
Renta writes into the merge fields your audience already has. Mailchimp does not check fields marked as required in the audience, so a contact can arrive without them.

Frequently asked questions

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