Adjusting your contact deduplication setting adjusts how and when we warn you about duplicate contacts across two different sequences. By default, you cannot add the same email address to the same sequence.
You can adjust this setting under your email settings in the safety section. Here's what each setting does:
Off - Do not deduplicate
This setting turns off deduplication entirely. We'll never warn you when a duplicate contact has been added to another sequence, if they're about to receive a message in another sequence, and if they've ever received a message.
Low - When actively sending another sequence's messages
We'll only warn you when another sequence has messages to send to the same email address. This will not trigger if the other sequence has no email sequence steps or is archived.
Medium - Messaged in the past or sending messages from another sequence
Along with warning you if they're about to receive a message, we will also warn you when they have received a message ever from any of your sequences regardless if it's active or archived. If they have never received a message or not about to, you will not be warned.
Here's an example of when it's recommended to adjust the setting to Medium:
If a contact appears in multiple sequences, they can be messaged again if the deduplication setting is set to low and the contact has replied in a different sequence. In this instance, it's best to select Medium instead of Low to prevent the contact from being messaged again in another sequence.
High - If it has ever been added to another sequence
The most extreme setting of them all. We'll warn you whenever a contact has ever been added to any other sequence, even if it has been archived.