Outlook/Gmail Add-In Setup Guide

You need AI email assistance where you actually write emails: inside your inbox. This guide shows you how to install and configure draft-generation buttons in Outlook and Gmail using three proven methods, from simple browser extensions to full API integrations.

Most professional services firms start with browser extensions (5-minute setup), then graduate to native add-ins when they need firm-wide deployment controls.

Works for both Gmail and Outlook Web. No IT approval required.

Install ChatGPT Writer or Compose AI:

1. Go to Chrome Web Store and search "ChatGPT Writer" or "Compose AI"
2. Click Add to Chrome, then Add Extension
3. Pin the extension icon to your toolbar (click puzzle piece icon, then pin)
4. Open Gmail or Outlook.com in your browser
5. Click the extension icon and sign in with your OpenAI or provider account

Configure the draft button:

1. Click the extension icon while viewing your inbox
2. Navigate to Settings > Shortcuts
3. Set keyboard shortcut to Ctrl+Shift+D (Windows) or Cmd+Shift+D (Mac)
4. Under "Compose Triggers," enable "Show button in compose window"
5. Save settings

Use it:

1. Open a new email or reply
2. Click the floating draft button (usually appears bottom-right of compose window)
3. Type your instruction: "Draft a follow-up to this client asking for outstanding documents for their tax return"
4. Review, edit, send

Limitation: Browser extensions only work in web versions of email clients, not desktop apps.

For firms using Outlook 2019, 2021, or Microsoft 365 desktop apps.

Prerequisites:

• Outlook desktop application (not Outlook.com web)
• Microsoft 365 Business Standard or higher
• Local admin rights OR IT-deployed add-in manifest

Install via AppSource (Individual Users):

1. Open Outlook desktop app
2. Click Home tab > Get Add-ins (or Store button in older versions)
3. Search "AI Mail Assistant" or "Copilot

   Copilot

   Click to read the full definition in our AI & Automation Glossary.

   for Outlook"
4. Click Add for your chosen add-in (popular options: Grammarly Business, Boomerang AI, or custom GPT integrations)
5. Accept permissions when prompted
6. Restart Outlook

Install via Manifest File (IT-Deployed):

If your IT team provides a custom manifest XML file:

1. Save the manifest file to C:\Users\[YourName]\AppData\Local\Microsoft\Outlook\Addins\
2. Open Outlook, go to File > Options > Add-ins
3. Click Go next to "Manage: COM Add-ins"
4. Click Add, browse to your manifest file location
5. Select the file, click OK
6. Check the box next to the add-in name, click OK

Configure the add-in:

1. Click the add-in icon in your Outlook ribbon (usually appears under Home or Message tab)
2. Sign in using your firm's SSO or API

   API

   Click to read the full definition in our AI & Automation Glossary.

   key
3. Navigate to Settings (gear icon within add-in panel)
4. Under "Quick Actions," enable "Draft Request Button"
5. Set your default prompt template: [DRAFT TYPE]: [CONTEXT FROM EMAIL THREAD]
6. Choose button placement: Ribbon vs. Right-click context menu
7. Save configuration

Create a custom Quick Step for one-click drafting:

1. Go to Home tab > Quick Steps > Create New
2. Name it "AI Draft Reply"
3. Add action: "Run a Script" (requires VBA, see below)
4. Assign shortcut key: Ctrl+Shift+A
5. Click Finish

VBA script for Quick Step (optional advanced setup):

Sub GenerateAIDraft()
    Dim objMail As Outlook.MailItem
    Set objMail = Application.ActiveInspector.CurrentItem
    
    ' Trigger your add-in's draft function
    ' This assumes your add-in exposes a COM interface
    ' Replace with your add-in's actual method call
    objMail.Body = "[AI_DRAFT_PLACEHOLDER]"
    objMail.Display
End Sub

Use it:

1. Open an email or start a reply
2. Click your add-in button in the ribbon OR press your Quick Step shortcut
3. The add-in panel opens with context from the email thread
4. Click "Generate Draft" or type a custom instruction
5. Review the draft in the compose window, edit as needed, send

For firms using Google Workspace (formerly G Suite).

Prerequisites:

• Google Workspace account (not free Gmail)
• Workspace admin approval for add-on installation (or user-installed if allowed)

Install from Google Workspace Marketplace:

1. Go to workspace.google.com/marketplace
2. Search "AI Email Assistant" or "GPT for Gmail"
3. Click the add-on (recommended: "AI Email Writer" or "Compose AI for Gmail")
4. Click Install > Continue
5. Select your Google Workspace account
6. Review permissions (will request: read/compose emails, access to contacts)
7. Click Allow

For admin-deployed installation:

Ask your IT admin to:

1. Log in to admin.google.com
2. Navigate to Apps > Google Workspace Marketplace apps
3. Search for your chosen add-on
4. Click the add-on, then "Admin Install"
5. Select organizational units to deploy to
6. Click Continue, then Accept permissions

Configure the add-on:

1. Open Gmail and compose a new message
2. Look for the add-on icon in the right sidebar (usually a colored square)
3. Click the icon to open the add-on panel
4. Click Settings (gear icon)
5. Connect your AI provider: Enter OpenAI API

   API

   Click to read the full definition in our AI & Automation Glossary.

   key or sign in to provider
6. Under "Compose Settings," enable "Show draft button in compose window"
7. Set default tone: Professional, Friendly, or Formal
8. Configure context awareness: Toggle "Include previous email thread" ON
9. Save settings

Set up keyboard shortcut (Chrome only):

1. Type chrome://extensions/shortcuts in Chrome address bar
2. Find your Gmail add-on in the list
3. Click in the shortcut field next to "Activate the extension"
4. Press Ctrl+Shift+D (or your preferred combo)
5. Close the tab

Use it:

1. Compose a new email or click Reply
2. Click the add-on icon in the right sidebar OR use your keyboard shortcut
3. In the add-on panel, type your instruction: "Draft a professional response declining this meeting request"
4. Click Generate
5. The draft appears in your compose window
6. Edit, then send

For firms building custom workflows or integrating with practice management systems.

When to use this:

• You want drafts generated automatically based on triggers (new client intake, document request, etc.)
• You need to log all AI-generated content in your DMS
• You want firm-specific templates and guardrails

Setup overview:

1. Obtain API

   API

   Click to read the full definition in our AI & Automation Glossary.

   credentials from OpenAI, Anthropic, or your AI provider
2. Use Zapier, Make.com, or custom code to connect email + AI
3. Create trigger: "When email received from [client domain]"
4. Action: "Send email body + custom prompt to AI API

   API

   Click to read the full definition in our AI & Automation Glossary.

   "
5. Action: "Create draft in email client with AI response"

Example Zapier setup:

1. Create new Zap: Gmail (trigger) > OpenAI (action) > Gmail (action)
2. Trigger: New Email Matching Search in Gmail
3. Search string: from:client@example.com subject:"document request"
4. OpenAI action: Send Prompt
5. Prompt template: Draft a professional email response to this document request. Include: acknowledgment, timeline (3 business days), list of documents we need from them. Email context: {{email_body}}
6. Gmail action: Create Draft
7. Draft body: {{openai_response}}
8. Turn on Zap

Cost: Approximately $0.002-0.02 per draft depending on email length and model used.

Before rolling out to your entire firm:

• [ ] Test with 3-5 pilot users for 2 weeks
• [ ] Document approved use cases (client emails yes, opposing counsel emails review first)
• [ ] Create prompt templates for common scenarios (engagement letters, status updates, document requests)
• [ ] Set up audit logging if required by your malpractice carrier
• [ ] Train staff on reviewing AI output (never send without reading)
• [ ] Add to onboarding checklist for new hires
• [ ] Establish monthly review: which emails are being drafted, any quality issues

Add-in doesn't appear in Outlook ribbon:

• Check File > Options > Add-ins > Manage COM Add-ins > verify it's checked
• Restart Outlook in safe mode: outlook.exe /safe
• Re-install the add-in

Gmail add-on shows "Authorization required" error:

• Go to myaccount.google.com/permissions
• Remove the add-on, then re-install and re-authorize

Drafts are generic or miss context:

• Verify "Include email thread" is enabled in settings
• Manually add context in your instruction: "Draft reply to THIS email about the Q3 audit"
• Check your prompt template includes {{email_body}} or equivalent variable

API

• Add a filter in your automation: "Only if draft doesn't already exist with subject line"
• Use email threading IDs to prevent re-processing the same conversation

Pick one method and install it today. Start with browser extensions if you're testing solo, or Outlook/Gmail add-ons if you're rolling out to a team.

Create three prompt templates for your most common email types (client updates, internal requests, meeting follow-ups) and save them in the add-in settings. You'll use these daily.