Free Outlook Add-in No account Lighten your emails.
Lighten your emails.
Lighten your impact.
MailLighter removes useless images, forgotten attachments and endless reply chains from your emails, in one click, directly from the Outlook ribbon.
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Attach
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Remove images
Keep latest 2 replies
Remove attachments
Full cleanup
Keep selection only
SettingsTo:team@company.com (12 recipients)
Sub:Re: Q4 Report — Final review
Hi all, please find below the updated version for review.
company_banner.png — 820 KB
report_Q4_final_v3.xlsx — 3.4 MB
— Original message (8 replies, 3 weeks of history) —
From: Marc · 14 Nov · Sent: Re: Re: Re: Re: Q4 report…
From: Marc · 14 Nov · Sent: Re: Re: Re: Re: Q4 report…
Full cleanup complete
Images: 1 removed (820 KB) · Attachments: 1 removed (3.4 MB)
Replies: 8 → 2 kept · Total saved: 4.2 MB
Images: 1 removed (820 KB) · Attachments: 1 removed (3.4 MB)
Replies: 8 → 2 kept · Total saved: 4.2 MB
300Bn
emails sent every day worldwide
daily volume 3–4%
of global greenhouse gas emissions from digital
GHG impact ~40%
lighter — average size reduction per cleaned email
average savings Real impact
One click. A measurable difference.
The concrete transformation on a classic email.
Heavy thread cleanup extreme real case
📧 Before
2.8 MB
8 embedded images
2 forgotten attachments
4 weeks of reply history
🌡️ ≈ 7.6 g CO₂ avoided per send 2 forgotten attachments
4 weeks of reply history
→
150×
lighter
lighter
✉️ After MailLighter
18 KB
Text only
2 most recent replies kept
Nothing unnecessary
🌿 5 recipients · 24-month storage 2 most recent replies kept
Nothing unnecessary
Typical thread cleanup everyday case
📧 Before
~210 KB
Signature logos and banners
5 replies in the thread
One small attachment
🌡️ ≈ 0.3 g CO₂ avoided per send 5 replies in the thread
One small attachment
→
~40%
lighter
lighter
✉️ After MailLighter
~120 KB
Clean signature
2 most recent replies kept
Smaller footprint, same message
🌿 5 recipients · 24-month storage 2 most recent replies kept
Smaller footprint, same message
Features
Five actions. One click.
Everything accessible directly from the Outlook ribbon. No configuration needed.
Full Cleanup
Runs all actions at once. Images, attachments, reply threads — cleaned in one go. A detailed summary shows exactly what was removed and how much space was saved.
Remove Images
Strips all embedded images from the body. Signature images are preserved.
Remove Attachments
Removes attached files from the thread. Inline signature images are preserved.
Keep 2 Replies
Trims long threads to the 2 most recent messages. Detects quoted blocks in all languages.
Keep Selection
Replace the entire thread with only the text you selected. Total precision.
100% Local
Runs entirely inside Outlook via Office.js. No data ever leaves your device.
Getting started
Up and running in 60 seconds.
No account to create, no complex setup.
1
Install the add-in
Download MailLighter from Microsoft Marketplace and add it to Outlook in seconds.
→
2
Compose your email
Write or reply as usual. The MailLighter menu appears in your ribbon.
→
3
Lighten before sending
Choose your action. MailLighter runs instantly and shows you what was cleaned.
Ready?
Start lightening your emails today.
Free, no account, no data collection. Install MailLighter in seconds.
Install for free on Marketplace Outlook Desktop & Web Windows & macOS Microsoft 365 & Exchange 100% Free