diff --git a/firestore-send-email/CHANGELOG.md b/firestore-send-email/CHANGELOG.md
index 6d30cd4a0..d70db6e19 100644
--- a/firestore-send-email/CHANGELOG.md
+++ b/firestore-send-email/CHANGELOG.md
@@ -1,3 +1,11 @@
+## Version 0.2.4
+
+fix: add missing 'headers' field to the mailOptions interface
+
+docs: update documentation to include 'headers' field
+
+fix: TTL expire type "week" fixed (#2455)
+
 ## Version 0.2.3
 
 fix: remove strict validation of email "from" field
diff --git a/firestore-send-email/PREINSTALL.md b/firestore-send-email/PREINSTALL.md
index db67bafb1..30ab98009 100644
--- a/firestore-send-email/PREINSTALL.md
+++ b/firestore-send-email/PREINSTALL.md
@@ -18,6 +18,29 @@ You can also optionally configure this extension to render emails using [Handleb
 
 When you configure this extension, you'll need to supply your **SMTP credentials for mail delivery**. Note that this extension is for use with bulk email service providers, like SendGrid, Mailgun, etc.
 
+#### Using custom headers
+
+You can add custom headers to your emails by including a `headers` field in the document you add to the Firestore collection. The `headers` field should be an object where each key is the header name and the value is the header value.
+
+## Example JSON with Custom Headers:
+```json
+{
+  "to": ["example@example.com"],
+  "message": {
+    "subject": "Test Email with Custom Headers",
+    "text": "This is a test email to see if custom headers work.",
+    "html": "<strong>This is a test email to see if custom headers work.</strong>"
+  },
+  "headers": {
+    "X-Custom-Header": "CustomValue",
+    "X-Another-Header": "AnotherValue",
+  }
+}
+```
+
+Add this document to the Firestore mail collection to send an email with custom headers.
+You can even include headers like 'List-Unsubscribe' to allow recipients to unsubscribe from your emails.
+
 #### Firestore-Send-Email: SendGrid Categories
 
 When using SendGrid (`SMTP_CONNECTION_URI` includes `sendgrid.net`), you can assign categories to your emails.
diff --git a/firestore-send-email/README.md b/firestore-send-email/README.md
index b12c67c37..8db815d18 100644
--- a/firestore-send-email/README.md
+++ b/firestore-send-email/README.md
@@ -26,6 +26,29 @@ You can also optionally configure this extension to render emails using [Handleb
 
 When you configure this extension, you'll need to supply your **SMTP credentials for mail delivery**. Note that this extension is for use with bulk email service providers, like SendGrid, Mailgun, etc.
 
+#### Using custom headers
+
+You can add custom headers to your emails by including a `headers` field in the document you add to the Firestore collection. The `headers` field should be an object where each key is the header name and the value is the header value.
+
+## Example JSON with Custom Headers:
+```json
+{
+  "to": ["example@example.com"],
+  "message": {
+    "subject": "Test Email with Custom Headers",
+    "text": "This is a test email to see if custom headers work.",
+    "html": "<strong>This is a test email to see if custom headers work.</strong>"
+  },
+  "headers": {
+    "X-Custom-Header": "CustomValue",
+    "X-Another-Header": "AnotherValue",
+  }
+}
+```
+
+Add this document to the Firestore mail collection to send an email with custom headers.
+You can even include headers like 'List-Unsubscribe' to allow recipients to unsubscribe from your emails.
+
 #### Firestore-Send-Email: SendGrid Categories
 
 When using SendGrid (`SMTP_CONNECTION_URI` includes `sendgrid.net`), you can assign categories to your emails.
diff --git a/firestore-send-email/extension.yaml b/firestore-send-email/extension.yaml
index d0b34a42a..a2bbe97ae 100644
--- a/firestore-send-email/extension.yaml
+++ b/firestore-send-email/extension.yaml
@@ -13,7 +13,7 @@
 # limitations under the License.
 
 name: firestore-send-email
-version: 0.2.3
+version: 0.2.4
 specVersion: v1beta
 
 displayName: Trigger Email from Firestore
diff --git a/firestore-send-email/functions/src/index.ts b/firestore-send-email/functions/src/index.ts
index 2af1518a6..1611a051e 100644
--- a/firestore-send-email/functions/src/index.ts
+++ b/firestore-send-email/functions/src/index.ts
@@ -114,7 +114,7 @@ function getExpireAt(startTime: Timestamp) {
       now.setDate(now.getDate() + value);
       break;
     case "week":
-      now.setDate(now.getDate() + value);
+      now.setDate(now.getDate() + value * 7);
       break;
     case "month":
       now.setMonth(now.getMonth() + value);
@@ -122,6 +122,9 @@ function getExpireAt(startTime: Timestamp) {
     case "year":
       now.setFullYear(now.getFullYear() + value);
       break;
+    default:
+      // Optionally handle unknown types
+      throw new Error(`Unknown TTLExpireType: ${config.TTLExpireType}`);
   }
   return Timestamp.fromDate(now);
 }
@@ -170,6 +173,7 @@ async function deliver(ref: DocumentReference): Promise<void> {
       subject: payload.message?.subject,
       text: payload.message?.text,
       html: payload.message?.html,
+      headers: payload?.headers,
       attachments: payload.message?.attachments,
       categories: payload.categories,
       templateId: payload.sendGrid?.templateId,