Mailchimp marketing sync.
Two separate Mailchimp integrations — a Marketing API that syncs bidder opt-ins to your audience, and an SMTP relay for transactional emails — plus the full setup steps, how it works for bidders, and how to resolve the most common problems.
Locating the Mailchimp settings
The control panel lives in your seller dashboard.
You'll find this control panel in your seller dashboard. Go to Settings › Subscribe Settings.
Step-by-step connection
Work down the page in order — each field unlocks the next part of the form.
Default Subscribe — the interest groups every new subscriber is added to automatically, without checking a box (e.g. a "General Newsletter" group).
Options shown for users — the groups presented as choices to your bidders on the sign-up form. You can also give each a friendly display name in the text box beside it (e.g. show
FINART_Q4_2024 as "Fine Art Updates").If you haven't selected a subscriber list or mapped any categories under "Options shown for users", the system automatically sets the status to Inactive when you save, because the connection is incomplete.
Create the Mailchimp webhook
This lets Mailchimp notify Bidsquare when contacts change — for example, when someone unsubscribes.
MY_SECRET_KEY with the actual Callback Secret Key you created in Step 2:https://www.bidsquare.com/callback/mailchimpWebhook?secret_key=MY_SECRET_KEY
How the integration works in detail
What "categories" and "interests" mean, and what happens when a bidder opts in.
Bidsquare uses the Mailchimp API to interact with Interest Categories and the Interests within them.
- Interest Category — a grouping in Mailchimp, such as "Art Styles" or "Collecting Fields".
- Interest — a specific choice within that category, such as "Modern Art", "Impressionism" or "Antique Furniture".
When you click Fetch, Bidsquare asks Mailchimp for all the Interest Categories and the Interests inside them for the selected audience.
- The Default Subscribe checkboxes set which interests are pre-ticked on the opt-in options a bidder sees in their My Account area.
- The Options shown for users checkboxes and text fields build the opt-in options shown in each bidder's My Account area — a custom version of your Mailchimp groups for bidders to choose from.
- When a bidder opts in from their My Account area and selects their interests, Bidsquare sends their email and chosen interests to Mailchimp against the groups you mapped.
Email support@bidsquare.com or call 1-800-657-0092 and we'll help you get connected.
What this integration is — and isn't
Understand the scope before you configure anything.
Bidsquare has two separate integrations with Mailchimp services. They do different things, require different setups, and are often confused with each other.
1 · Mailchimp Marketing API
Connects your bidder accounts to a Mailchimp audience. Bidders opt in to interest groups from their My Account › My Alerts page. Bidsquare syncs name, email, and their chosen opt-ins to Mailchimp approximately every 24 hours.
This is what this guide covers.
2 · Mailchimp Transactional (SMTP)
Routes your system's transactional emails (invoices, registration approvals, outbid notices) through Mailchimp's sending infrastructure so they arrive from your own domain address.
Covered in the SMTP Email Relay guide. Requires a separate paid add-on.
The sync passes name, email address, and the interest opt-ins each bidder has selected in My Alerts. That's it. It does not pass addresses, phone numbers, purchase history, bid history, consignment data, watchlist items, or any transactional information. It is a marketing segmentation tool, not a full CRM sync.
Mailchimp merges records by email address — it does not create duplicates or overwrite existing contact data for fields Bidsquare doesn't send.
How it works for bidders
Where interest options appear — and where they don't.
Once the connection is active, bidders manage their Mailchimp opt-ins from inside their account on your site. There is no opt-in step during the standard registration or signup flow.
The "Options shown for users" field in your connection settings controls what appears in My Account › My Alerts — not the registration or newsletter signup form. A bidder who registers but never visits My Alerts will be added to your Mailchimp audience with any Default Subscribe groups applied, but with no individual interest selections.
A basic "add me to your mailing list" option in the signup flow is possible as a custom addition to White-Label sites, subject to scoping and may be chargeable. Speak to your Bidsquare account manager if this is a requirement.
Common problems
The issues that come up most often during and after setup.
https://www.bidsquare.com/callback/mailchimpWebhook?secret_key=YOUR_KEY