Subscribers & contacts

Every sync ends the same way: a contact is added to or updated in your own email tool. This page explains how QuillJet decides which contact to touch, what that contact looks like once it lands, and how QuillJet respects the rules your tool already enforces around consent and unsubscribes.

Matched by email, never duplicated

QuillJet identifies a contact by email address. Before creating anything, it checks whether that email already exists in the target list or audience:

If it exists, QuillJet updates that contact with the latest fields and tags.
If it does not exist, QuillJet creates it.

The same person is never added twice. This is called an upsert (update or insert), and it is why re-syncing a returning shopper is safe. For the bigger picture of how a delivery reaches this point, see how syncing works.

What the subscriber looks like in your tool

The contact QuillJet builds carries an email, an optional first and last name, any mapped or automatic fields, and any tags from the rule. Each email tool stores these in its own way:

Mailchimp: the contact is added to your audience with FNAME and LNAME merge fields, plus any merge fields you mapped, and tags are applied as active tags.
Klaviyo: the profile gets first_name and last_name and standard attributes, with anything non-standard stored as custom properties, then added to your list.
Brevo: the contact is created or updated with FIRSTNAME, LASTNAME, and your mapped attributes, and added to your list.
The other tools (MailerLite, ActiveCampaign, Omnisend, GetResponse) follow the same idea: a contact with name, mapped fields, and tags.

See what syncs where for exactly which Webflow values become which fields.

Merge fields vs attributes vs custom fields

Different tools use different words for the same idea, an extra piece of data attached to a contact:

Mailchimp calls them merge fields (for example FNAME, LNAME, ORDER_TOTAL), and they are defined per audience.
Brevo calls them attributes, defined at the account level.
Klaviyo has a fixed set of standard attributes (like first_name), and everything else becomes a custom property.

When you build a mapping, QuillJet reads the writable fields from your connected tool so you point Webflow sources at real targets. The names above (like ORDER_ID and ORDER_TOTAL) are the field keys QuillJet writes; make sure a matching field exists in your tool if you want it stored under that name. Learn more in field mapping.

If the contact already exists

An existing contact is updated, not replaced wholesale. QuillJet writes the fields and tags from this sync onto the contact. Fields you did not map are left as they are in your tool. Because matching is by email, a shopper who orders again, or who both fills a form and buys, ends up as one contact that accumulates the tags and fields from each sync.

Tip: If you want a value locked regardless of what the event contains, use a constant in the rule. Constants always win over mapped and automatic values.

Unsubscribes and your tool's rules

QuillJet upserts contact data. It does not send email and it does not override a contact's subscription, consent, or unsubscribe state in your tool. Your email tool governs who can be emailed.

If someone unsubscribed in your tool, syncing them again through QuillJet updates their fields and tags but does not resubscribe them or bypass their opt-out. Sending, suppression lists, double opt-in, and consent all remain your tool's responsibility. QuillJet's job ends at delivering an up-to-date contact into the list or audience you chose.