Does Mixpanel Cohort Sync with Facebook Ads support custom email properties or only the standard $email?

Pawel A. · 2026-08-28T16:08:19.889Z

@kapa.ai When setting up the native Cohort Sync with Facebook Ads, does Mixpanel automatically look exclusively for the standard $email property, or is there a way to choose a different user property (e.g., a custom property holding a real email address instead of an Apple Private Relay one)?

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kapa.ai
APP
·
(edited)·
Thinking completed
Cohort sync & integration · 5 sources
Cohort sync troubleshooting · 3 sources
Cohort sync integrations · 3 sources
User data & integrations · 10 sources
Done · 21 sources
Based on the knowledge sources, Mixpanel's Facebook Ads Cohort Sync uses the standard $email reserved profile property specifically — there is no documented option to map a custom user property as the email source for this integration. Here's what the docs say about how matching works and what gets exported:
Matching Logic
"Meta uses email addresses as the primary identifier to match users in your cohort with users in their system. If an email address is not available, Meta may instead attempt to match using other identifiers such as a phone number, first and last name, or a device advertising ID (depending on your connection setup)." [Facebook Ads integration]

Exported Properties
The Cohort Sync feature exports a fixed set of reserved properties only:
$distinct_id $first_name $last_name $partner_user_id $email $phone
No other user properties are exported. [Cohort Sync overview]
What is configurable
During the Facebook Ads connector setup, you can optionally select a user property where you store the device advertising ID as an alternative/supplementary identifier — but there is no equivalent option to substitute a custom property for $email. [Facebook Ads integration]
Practical Implication for Apple Private Relay Emails
The knowledge sources do not explicitly address the Apple Private Relay scenario. However, since the export is locked to $email, the only workaround within the current integration would be to store the real (non-relay) email address in the $email profile property when you have it. There is no documented way to point the sync at a different custom property holding the real email instead. If this is a critical need, you may want to reach out to Mixpanel support directly, as the docs don't cover this specific case.
ℹ️ Tip: Mention @kapa.ai in the thread for follow-ups or DM the app for 1-to-1 help.

kapa.ai
APP
·
(edited)·
Thinking completed
Cohort sync & integration · 5 sources
Cohort sync troubleshooting · 3 sources
Cohort sync integrations · 3 sources
User data & integrations · 10 sources
Done · 21 sources
Based on the knowledge sources, Mixpanel's Facebook Ads Cohort Sync uses the standard $email reserved profile property specifically — there is no documented option to map a custom user property as the email source for this integration. Here's what the docs say about how matching works and what gets exported:
Matching Logic
"Meta uses email addresses as the primary identifier to match users in your cohort with users in their system. If an email address is not available, Meta may instead attempt to match using other identifiers such as a phone number, first and last name, or a device advertising ID (depending on your connection setup)." [Facebook Ads integration]

Exported Properties
The Cohort Sync feature exports a fixed set of reserved properties only:
$distinct_id $first_name $last_name $partner_user_id $email $phone
No other user properties are exported. [Cohort Sync overview]
What is configurable
During the Facebook Ads connector setup, you can optionally select a user property where you store the device advertising ID as an alternative/supplementary identifier — but there is no equivalent option to substitute a custom property for $email. [Facebook Ads integration]
Practical Implication for Apple Private Relay Emails
The knowledge sources do not explicitly address the Apple Private Relay scenario. However, since the export is locked to $email, the only workaround within the current integration would be to store the real (non-relay) email address in the $email profile property when you have it. There is no documented way to point the sync at a different custom property holding the real email instead. If this is a critical need, you may want to reach out to Mixpanel support directly, as the docs don't cover this specific case.
ℹ️ Tip: Mention @kapa.ai in the thread for follow-ups or DM the app for 1-to-1 help.

1 comment

Thinking completed

Matching Logic

Exported Properties

What is configurable

Practical Implication for Apple Private Relay Emails

Thinking completed

Matching Logic

Exported Properties

What is configurable

Practical Implication for Apple Private Relay Emails