Merge pull request #7370 from segmentio/sendgrid-lists

[SendGrid LIsts] - updating some wording

Author: forstisabella

src/connections/destinations/catalog/actions-sendgrid-audiences/index.md

@@ -79,7 +79,10 @@ At least one of the following identifier types is required when syncing members
  - Phone Number ID (must be in [E.164](https://www.twilio.com/docs/glossary/what-e164){:target="_blank”} format)
  - External ID 
 
-To sync Engage users to a list using Anonymous ID, Phone Number ID, and External ID identifier types, complete the following configuration steps: 
+> warning ""
+> If you provide more than one type of identifier for each user in your initial sync, you must send all of those identifier types for any future updates to that Contact.
 
-1. Configure [ID Sync](/docs/engage/trait-activation/id-sync/) to include Anonymous ID, Phone Number ID, or External ID identifiers when syncing users from an Engage Audience to the SendGrid List. 
-2. Map the Anonymous ID, Phone Number ID, and External ID identifiers using the [Sync Audience ](#sync-audience-action) Action's Anonymous ID, Phone Number ID, and External ID fields. 
+To sync Engage users to a SendGrid list using an identifier type other than email, complete the following additional steps:
+
+1. Configure [ID Sync](/docs/engage/trait-activation/id-sync/) to include a value for the identifier when syncing users from an Engage Audience to the SendGrid List. 
+2. Map the identifier using the [Sync Audience Action](#sync-audience-action)'s mapping field.