AliasCue for Gmail

Never send from the wrong alias again.

AliasCue for Gmail colour-codes Gmail compose windows based on the selected 'Send Mail As' identity, including plus-addresses.

If you manage personal, business, client, family, role-based, domain or plus-address identities from one Gmail account, AliasCue gives you a clear visual cue before you press Send.

Copyright © 2026 R J Corless. All rights reserved.

What it does

AliasCue for Gmail helps make the active sending alias obvious while composing, replying or forwarding in Gmail.

It can apply an identity-specific:

• accent border
• top colour strip
• identity badge
• optional tint background

It supports full email matching, so addresses such as these can each have their own colour:

yourname@gmail.com
yourname+consulting@gmail.com
yourname+accounts@gmail.com
you@example.com

Why it exists

Gmail can auto-select different 'Send Mail As' identities depending on the message you are replying to, forwarding or composing.

That behaviour is useful, but the selected sender can be visually subtle. If you use several aliases from one Gmail account, it is easy to miss which address is currently active.

AliasCue makes the sender context visible at a glance.

What it does not do

AliasCue for Gmail does not:

• use the Gmail API
• read email message contents
• send your settings or identity list to an external server
• manage Gmail signatures
• change how Gmail sends email
• replace Gmail's native 'Send Mail As' settings

For signatures, use Gmail's native signature settings.

Installation for testing

This is currently an unpacked extension build.

1. Download the latest release ZIP.
2. Unzip it.
3. Open your browser's extensions page:
   • Edge: edge://extensions
   • Chrome: chrome://extensions
4. Enable Developer mode.
5. Click Load unpacked.
6. Select the unzipped extension folder.
7. Open Gmail.

Testing feedback wanted.

AliasCue for Gmail is currently an early tester build.

It is most useful for people who use Gmail with multiple 'Send Mail As' identities, custom domains, aliases or plus-addresses.

If you test it, feedback is especially welcome on:

• whether the correct sending alias is detected
• whether new compose, reply and forward windows are styled correctly
• whether manual From identity changes update the styling correctly
• whether multiple compose windows behave properly
• whether Gmail remains stable when left open for long periods
• whether Gmail stays logged in after browser restarts or PC reboots
• which browser you tested with, such as Edge, Chrome or another Chromium browser
• whether you used local storage or browser-account sync

Please report issues through GitHub Issues, including your browser, browser version, operating system and a short description of what happened.

Do not include private email contents, passwords, authentication codes or sensitive screenshots in issue reports.

Pinning the extension icon to the toolbar

After loading the extension, the browser may hide the icon inside the Extensions menu.

Microsoft Edge

1. Click the Extensions button in the toolbar. It usually looks like a puzzle piece.
2. Find AliasCue for Gmail in the list.
3. Choose the visibility or toolbar option, such as Show in toolbar.
4. The AliasCue icon should now appear directly on the toolbar.

You can also open edge://extensions, find AliasCue for Gmail, and check the available toolbar or details options from there.

Google Chrome

1. Click the Extensions button in the toolbar. It usually looks like a puzzle piece.
2. Find AliasCue for Gmail.
3. Click the pin icon beside it.
4. The AliasCue icon should now appear directly on the toolbar.

Opening the popup and Options page

Once the icon is visible on the toolbar:

1. Click the AliasCue for Gmail icon.
2. The toolbar popup will open.
3. Use Open options to manage identities, colours, display settings, sync and backup.
4. Use Open Gmail to jump to Gmail or open it in a new tab.

Other ways to open Options:

• Right-click the AliasCue toolbar icon and choose Options, if your browser shows that command.
• Open edge://extensions or chrome://extensions, find AliasCue for Gmail, then open its Details or Extension options page.

First setup

1. Open Options.
2. Add each Gmail 'Send Mail As' identity you want to colour-code.
3. Enter the full sender address exactly.
4. Include plus-addresses exactly, for example yourname+consulting@gmail.com.
5. Give each identity a friendly label.
6. Pick a colour.
7. Use the Compose preview panel to check how the badge, strip, border and tint will look.
8. Press Save changes.
9. Refresh Gmail if it was already open.

Detected identities

If Detect new identities is enabled, AliasCue can notice unconfigured sender addresses seen in Gmail and list them under Detected identities.

From there, you can add them to your configured identity list.

Detected identities remain local to the browser.

Storage and sync

By default, AliasCue stores configured identities and display settings locally in the browser.

The Options page includes:

Sync settings using browser account

When enabled, configured identities, colours and display options are saved using browser sync storage where supported by the browser.

Detected identities remain local to the browser.

Backup and restore

The Options page includes:

• Export settings
• Import settings

Use these to back up your configuration or move it to another browser profile.

Do not share exported settings publicly unless you have checked that they do not contain personal or business email addresses.

Updating an unpacked test build

To test upgrades without losing local settings, do not remove the extension.

1. Keep one permanent development folder.
2. Load that folder once as an unpacked extension.
3. For each new build, copy the new files into that same folder and overwrite the old files.
4. Press Reload on the existing extension card.

If the extension ID changes, the browser is treating it as a different extension and local storage may not carry across.

Privacy notes

AliasCue for Gmail only needs:

• storage permission
• access to https://mail.google.com/*

It reads the selected From identity visible in Gmail's compose window structure so it can apply the correct visual styling.

It does not read email message contents.

It does not use external servers.

Diagnostics copied from the Options page do not include email addresses, labels or message contents.

Known limitations

Gmail's web interface may change over time. If Google changes the compose window structure, AliasCue may need an update.

Because this is currently an unpacked test build, browser behaviour can vary depending on profile state, extension ID, sync settings and how the extension is loaded.

Troubleshooting

The compose window is not colour-coded

Try the following:

1. Confirm the extension is enabled.
2. Confirm the Gmail tab has been refreshed after saving Options.
3. Confirm the sender address in Gmail exactly matches an identity in Options.
4. Check that the identity is enabled.
5. Check that display options such as badge, strip, border or tint are enabled.

The icon is not visible

The browser may have hidden it inside the Extensions menu.

Pin or show the icon from the Extensions menu using the instructions above.

My settings disappeared after updating

For unpacked builds, settings are tied to the extension ID.

If you remove the extension and load a new folder, the browser may treat it as a different extension.

For upgrade testing, keep the same loaded folder and overwrite the files inside it, then press Reload.

Gmail looks unusual after testing

Disable the extension from the toolbar popup or browser extensions page, then refresh Gmail.

If needed, remove the unpacked extension from the browser extensions page.

Smoke-test checklist

Before treating a build as stable, test:

• new compose
• reply
• forward
• manual From identity change
• multiple compose windows at the same time
• disabled identity
• global enabled/disabled toggle
• detected identity add flow
• duplicate identity warning
• invalid email warning
• export settings
• import settings
• local storage mode
• browser sync mode, if used
• browser restart with Gmail open
• PC restart with Gmail open

Support development

AliasCue for Gmail is free to use.

If it helps you avoid sending from the wrong alias, you may choose to support future development.

Donation/support link to be added.

Disclaimer

AliasCue for Gmail is an independent browser extension.

It is not affiliated with, endorsed by, or sponsored by Google LLC.

Gmail is a trademark of Google LLC.

Changelog

v0.8.6

• Renamed user-facing product text to AliasCue for Gmail.
• Updated manifest name, extension titles, Options page, popup, diagnostics, README and NOTICE.
• Added the extension icon to the toolbar popup presentation.
• Kept internal storage keys unchanged for upgrade compatibility.

v0.8.5

• Expanded README instructions.
• Added guidance for making the extension icon visible on the Edge and Chrome toolbar.
• Added instructions for opening the toolbar popup and Options page.
• Added a basic Options workflow for configuring identities and colours.

v0.8.4

• Low-impact Gmail runtime patch.
• Removed the continuous Gmail-wide MutationObserver.
• AliasCue now scans in short bursts after page load or user interaction instead of continuously watching an idle Gmail tab.
• Temporary compose detection observer disconnects automatically after a few seconds.
• Runtime listeners, timers and temporary observers are stopped when the extension is disabled or the page is hidden/unloaded.

v0.8.3

• Stability-first Gmail content script patch.
• MutationObserver no longer watches character-data changes.
• Runtime observer and event listeners stop when the extension is disabled.
• Runtime timers are cleared on page hide/unload to reduce shutdown churn.
• Scan cadence is less aggressive.
• Detected identity writes are delayed and skipped when the page is hidden.
• Updated wording to use 'Send Mail As'.
• Added the updated transparent icon set and popup header icon.

v0.8.2

• Hard-patched validation wording so user-facing messages do not refer to row numbers.
• Added an Options-page console marker to make it easier to confirm the loaded build.

v0.8.1

• Reworded validation messages so they refer to highlighted identities rather than row numbers.

v0.8.0

• Added stronger live validation for duplicate and invalid identity rows.
• Save is disabled while validation errors are present.
• Added a Copy diagnostics button that excludes email addresses and message contents.
• Added copyright notice using R J Corless.
• Added NOTICE.txt.
• Cleaned README for public/testing distribution.