What are contacts?
Contacts are the people you send emails to. Every recipient in SendKit is stored as a contact with their email address and optional profile information. You can create contacts manually, via the API, or let SendKit do it automatically.Automatic contact creation
Every time you send an email through SendKit — via API, campaign, or automation — the recipients (to, cc, bcc) are automatically saved as contacts. You don’t need to import or pre-register them. This means your contact list is always up to date with everyone you’ve ever emailed.If a contact with the same email already exists, SendKit skips creation. Emails are normalized to lowercase to prevent duplicates.
Contact fields
Every contact has the following built-in fields:| Field | Required | Description |
|---|---|---|
| Yes | The contact’s email address (unique per team) | |
| First name | No | First name |
| Last name | No | Last name |
| User ID | No | An external identifier to link the contact to a user in your system |
| Subscribed | Auto | Whether the contact is subscribed to marketing emails |
Subscription status
Each contact has a subscription toggle. Unsubscribed contacts are excluded from marketing campaigns but can still receive transactional emails via the API. You can toggle subscription status from the contact detail page or via the API.Organizing contacts
SendKit gives you two ways to group contacts:- Lists — Static groups you manage manually. Add or remove contacts explicitly.
- Segments — Dynamic groups based on filters. Contacts are included automatically when they match your conditions.
Deleting contacts
Contacts are soft-deleted — they’re removed from your active contact list but the data is preserved. This ensures email delivery history and analytics remain intact.FAQ
Do I need to create contacts before sending emails?
Do I need to create contacts before sending emails?
No. SendKit automatically creates contacts from your email recipients. You can also create them manually or via the API if you want to set up contacts before sending.
Are contacts shared across my team?
Are contacts shared across my team?
What happens if I send to the same email twice?
What happens if I send to the same email twice?
SendKit uses the existing contact — it doesn’t create a duplicate. Email addresses are unique per team.
Can I add custom fields to contacts?
Can I add custom fields to contacts?
Yes. Use Properties to define custom attributes with different types (text, number, date) and optional fallback values.