docs: Add Email Notifications info

docs/docs/administration/email-notification.mdx

@@ -0,0 +1,23 @@
+# Email Notifications
+
+Immich supports the option to send notifications via Email for the following events:
+
+- Creating a new user
+- Notifying a user when they get added to a shared album
+- Informing other users about the addition of new assets to a shared album
+
+## SMTP settings
+
+You can access the settings panel from the web at `Administration -> Settings -> Notification settings`
+
+Under Email, enter the following details to connect with SMTP servers.
+
+You can use the following [guide](/docs/guides/smtp-gmail) to use Gmail's SMTP server.
+
+<img src={require('./img/email-settings.png').default} width="80%" title="SMTP settings" />
+
+## User's notifications settings
+
+Users can manage their email notification settings from their account settings page on the web. They can choose to turn email notifications on or off for the following events:
+
+<img src={require('./img/user-notifications-settings.png').default} width="80%" title="User notification settings" />

docs/docs/administration/user-management.mdx

@@ -13,6 +13,20 @@ Immich supports multiple users, each with their own library.
 
 <UserCreate />
 
+## Send new user email notification
+
+:::note
+This option is only available if an SMTP server has been configured in the administrator settings.
+:::
+
+Admin can send a welcome email if the Email option is set, you can learn here how to set up the SMTP server in Immich.
+
+<img
+  src={require('./img/send-user-email-notification.webp').default}
+  width="40%"
+  title="Send user email notification"
+/>
+
 ## Set Storage Quota For User
 
 Admin can specify the storage quota for the user as the instance's admin; once the limit is reached, the user won't be able to upload to the instance anymore.

docs/docs/guides/smtp-gmail.md

@@ -0,0 +1,20 @@
+# SMTP settings using Gmail
+
+This guide walks you through how to get the information you need to set up your Immich instance to send emails using Gmail's SMTP server.
+
+## Create an app password
+
+From your Google account settings
+
+- Add [2-Step Verification](https://support.google.com/accounts/answer/185839) to your Google account (Required)
+- [Create an app password](https://myaccount.google.com/apppasswords).
+
+At the end of creating your app passwords, a password will be displayed; save it, it will be used for the password field when setting up the SMTP server in Immich.
+
+<img src={require('./img/google-app-password.webp').default} title="Authorised redirect URIs" />
+
+## Entering the SMTP credential in Immich
+
+Entering your credential in Immich's email notification settings at `Administration -> Settings -> Notification Settings`
+
+<img src={require('./img/email-settings.png').default} width="80%" title="SMTP settings" />