docs(firestore-send-email): add docs for ttl setup (#2260)

Author: cabljac

firestore-send-email/CHANGELOG.md

@@ -2,6 +2,8 @@
 
 feat - add SendGrid category support
 
+docs - add instructions for setting up Firestore TTL policies for the `delivery.expireAt` field.
+
 ## Version 0.1.34
 
 fixed - SendGrid v3 issues (#2020)

firestore-send-email/POSTINSTALL.md

@@ -61,6 +61,14 @@ Add this document to the Firestore mail collection to send categorized emails.
 
 For more details, see the [SendGrid Categories documentation](https://docs.sendgrid.com/ui/sending-email/categories).
 
+### Automatic Deletion of Email Documents
+
+To use Firestore's TTL feature for automatic deletion of expired email documents, the extension provides several configuration parameters.
+
+The extension will set a TTL field in the email documents, but you will need to manually configure a TTL policy for the collection/collection group the extension targets, on the `delivery.expireAt` field.
+
+Detailed instructions for creating a TTL field can be found in the [Firestore TTL Policy documentation](https://firebase.google.com/docs/firestore/ttl).
+
 
 ### Monitoring
 

firestore-send-email/PREINSTALL.md

@@ -64,6 +64,14 @@ To use your Outlook/Hotmail email account with this extension, you'll need to ha
 
 Before installing this extension, make sure that you've [set up a Cloud Firestore database](https://firebase.google.com/docs/firestore/quickstart) in your Firebase project.
 
+#### Automatic Deletion of Email Documents
+
+To use Firestore's TTL feature for automatic deletion of expired email documents, the extension provides several configuration parameters.
+
+The extension will set a TTL field in the email documents, but you will need to manually configure a TTL policy for the collection/collection group the extension targets, on the `delivery.expireAt` field.
+
+Detailed instructions for creating a TTL field can be found in the [Firestore TTL Policy documentation](https://firebase.google.com/docs/firestore/ttl).
+
 #### Billing
 To install an extension, your project must be on the [Blaze (pay as you go) plan](https://firebase.google.com/pricing)
 

firestore-send-email/README.md

@@ -72,6 +72,14 @@ To use your Outlook/Hotmail email account with this extension, you'll need to ha
 
 Before installing this extension, make sure that you've [set up a Cloud Firestore database](https://firebase.google.com/docs/firestore/quickstart) in your Firebase project.
 
+#### Automatic Deletion of Email Documents
+
+To use Firestore's TTL feature for automatic deletion of expired email documents, the extension provides several configuration parameters.
+
+The extension will set a TTL field in the email documents, but you will need to manually configure a TTL policy for the collection/collection group the extension targets, on the `delivery.expireAt` field.
+
+Detailed instructions for creating a TTL field can be found in the [Firestore TTL Policy documentation](https://firebase.google.com/docs/firestore/ttl).
+
 #### Billing
 To install an extension, your project must be on the [Blaze (pay as you go) plan](https://firebase.google.com/pricing)