added docs for sim mailer

Author: waleedlatif1

apps/docs/content/docs/en/mailer/index.mdx

@@ -0,0 +1,66 @@
+---
+title: Sim Mailer
+description: Send emails to your workspace and let Sim handle them as tasks.
+---
+
+import { Callout } from 'fumadocs-ui/components/callout'
+
+Sim Mailer gives your workspace a dedicated email address. Forward or send emails to it and Sim will process them as tasks — reading the subject, body, and any attachments, then replying to the thread with the result.
+
+This means you can interact with Sim directly from your email client without switching apps.
+
+## Getting Started
+
+1. Navigate to **Settings** → **Inbox**
+2. Toggle the inbox on
+3. Optionally choose a custom address prefix (e.g., `acme` → `acme@mothership.sim.ai`)
+4. Copy your inbox address and start sending emails
+
+If you skip the custom prefix, one is generated automatically.
+
+<Callout type="info">
+  Changing your address creates a new inbox. The old address stops working immediately.
+</Callout>
+
+## What You Can Send
+
+Write your email like you would to a colleague. The subject and body become the task prompt.
+
+**Attachments are fully supported.** Images, PDFs, and documents (up to 10 MB each) are read by Sim and displayed inline in the conversation — image attachments show as previews, just like when you upload them directly in the chat.
+
+| Good email | Why it works |
+|------------|-------------|
+| "Summarize the attached PDF and list action items" | Clear task with an attachment |
+| "What's in this image?" with a photo attached | Sim reads and describes the image |
+| "Draft a reply to this forwarded thread" | Uses the email body as context |
+
+## Allowed Senders
+
+Only authorized senders can create tasks. Emails from anyone else are automatically rejected.
+
+- **Workspace members** are allowed by default — no setup needed
+- **External senders** can be added manually with an optional label for easy identification
+
+Manage your allowed senders list in **Settings** → **Inbox** → **Allowed Senders**.
+
+## Tracking Tasks
+
+Every email becomes a task you can track in **Settings** → **Inbox**:
+
+- **Search** by subject, sender, or body content
+- **Filter** by status to find what you need
+- **Click** any completed or failed task to jump to the full conversation
+
+### Task Statuses
+
+| Status | Meaning |
+|--------|---------|
+| **Received** | Email accepted, queued for processing |
+| **Processing** | Sim is actively working on it |
+| **Completed** | Done — the result was sent as an email reply |
+| **Failed** | Something went wrong during execution |
+| **Rejected** | Email blocked (sender not allowed, automated sender, or rate limit exceeded) |
+
+## Conversations
+
+Each email task creates a conversation in your workspace. You can continue the conversation from the Sim chat interface, and any follow-up emails in the same thread are linked to the same conversation.

apps/docs/content/docs/en/meta.json

@@ -10,6 +10,7 @@
     "connections",
     "mcp",
     "copilot",
+    "mailer",
     "skills",
     "knowledgebase",
     "variables",