Microsoft Outlook does not include a way to keep the original attachments when you reply to an email — you have to install a free third-party add-in. The most reliable option is Reply with Attachment by IvaSoft (ivasoft.com/replywithatt). After installing and enabling it, the original attachments are automatically included whenever you click Reply, Reply All, or Forward.
Applies to: Classic Outlook for Microsoft 365 / Outlook 2021 / 2019 on Windows 10 (22H2) and Windows 11 (23H2, 24H2, 25H2) | Last updated: May 4, 2026
Key Takeaways
- Outlook does not include this feature — by design, replies do not carry attachments forward; you need an add-in to change that
- Reply with Attachment by IvaSoft is the long-running solution and works on classic Outlook for Microsoft 365, Outlook 2021, 2019, and 2016
- The free demo works indefinitely — it shows a small reminder pop-up each time you reply, but never expires
- This add-in only works in classic (desktop) Outlook — the New Outlook for Windows and the web version do not support COM add-ins
- Requires .NET Framework — the installer downloads it automatically if your PC does not already have it
Quick Steps
- Download
replywithatt-demo.zipfrom ivasoft.com/replywithatt.shtml - Right-click the ZIP and choose Extract All
- Run the extracted setup, accept the licence, and let it install .NET Framework if prompted
- Close Outlook completely, then reopen it
- Confirm Reply with Attachment Demo shows up under File > Options > Add-ins
- Open an email with attachments and click Reply or Reply All — attachments are included automatically
Why Outlook Drops Attachments on Reply
This is one of the longest-running complaints about Outlook, and it is intentional behaviour, not a bug. Microsoft removes the original attachments from replies and reply-alls to reduce mailbox bloat — every reply that re-attached the same files would multiply storage use across the conversation. The trade-off is that for genuine workflows where the recipients need to see the same file with your reply attached, you have to do something Outlook does not support natively.
The fix is a COM add-in that hooks into the reply event and re-attaches the original files automatically. The one I recommend, and the one I have used myself for years, is Reply with Attachment from IvaSoft.
Step 1: Download the Reply with Attachment Add-In
Open your browser and go to the official IvaSoft Reply with Attachment page. Click the replywithatt-demo.zip link to download the installer ZIP — it is small, around 2 MB.
Alternative: A different developer ships a similarly-named add-in at replywithattachment.com. It works much the same way and is worth trying if the IvaSoft installer fails on your system.
Step 2: Extract and Run the Installer
Open your Downloads folder, right-click replywithatt-demo.zip, and choose Extract All. Pick a location and click Extract. Open the new folder and double-click the .exe setup file inside.
Click Accept on the licence agreement. If your PC does not already have the right version of .NET Framework, the installer downloads and installs it for you — let it finish before continuing. Once .NET is sorted, click Next through the remaining wizard screens and let the installation complete.
Click Close when the wizard finishes.
Step 3: Restart Outlook and Verify the Add-In
If Outlook is open, close it completely and reopen it — add-ins are only registered at startup. After the restart, the new Reply with Attachment button appears on the ribbon when you have an email selected.
If the button is not visible, check that the add-in is enabled. Go to File > Options > Add-ins. Under Active Application Add-ins, you should see Reply with Attachment Demo. If it is in the Disabled or Inactive section, change the Manage dropdown at the bottom to COM Add-ins, click Go, tick the box next to it, and click OK.
Step 4: Reply to an Email and Keep the Attachments
Open any email that has attachments. Click Reply, Reply All, or Forward. The original attachments are automatically copied into the new message — no extra clicks required.
Because this is the demo version, a small reminder window appears each time you reply, suggesting you upgrade to the paid licence. The pop-up is mildly annoying but the demo itself is fully functional and never expires. If you reply to attachment-laden emails dozens of times a day, the paid version is worth the cost just to be rid of the prompt.
How to Uninstall the Add-In
If you decide you no longer need it, removal is a normal app uninstall. Right-click the Start button and choose Installed apps on Windows 11, or Apps and Features on Windows 10. Scroll to Reply with Attachment Demo, click the three-dot menu, choose Uninstall, and confirm.
Restart Outlook after uninstalling and the add-in is gone. If anything stubborn lingers, see my guide on force-deleting undeletable files.
Related Outlook Guides
- How to restore Classic Outlook in Microsoft 365 — necessary if Microsoft has switched you to New Outlook
- Prevent the New Outlook from installing on Windows 11 — registry tweak to keep Classic Outlook in place
Frequently Asked Questions
Does Reply with Attachment work in the New Outlook for Windows?
No. The New Outlook for Windows and Outlook on the web do not support COM add-ins. This add-in only works in classic Outlook (the desktop version installed with Microsoft 365, Outlook 2021, 2019, and 2016). If you have been moved to New Outlook, follow my guide on restoring Classic Outlook first.
Is the Reply with Attachment demo really free forever?
Yes. The demo never times out. Every reply you send shows a small pop-up reminding you the paid version exists, but the actual attachment-keeping feature works without restriction. If the pop-up bothers you, the paid licence is a one-time purchase per machine.
What if the Reply with Attachment button does not appear after I install it?
Close Outlook completely (check Task Manager to confirm no Outlook process is running) and reopen it. If the button still does not appear, go to File > Options > Add-ins, change the Manage dropdown to COM Add-ins, click Go, tick Reply with Attachment Demo, and click OK. If it is in the Disabled list, click Disabled Items and re-enable it from there.
Which versions of Outlook does this work with?
Classic Outlook for Microsoft 365 (current channel), Outlook 2021, Outlook 2019, and Outlook 2016. It does not work with the New Outlook for Windows, Outlook on the web (OWA), Outlook Mobile, or Outlook for Mac.
Are there alternatives to Reply with Attachment?
Yes. Reply With Attachment by another developer offers a similar feature set and is worth trying if the IvaSoft version does not work on your build of Outlook. There are also a few VBA macros floating around that do the same job, but they require trusting macros and are fiddly to set up — an add-in is the cleaner route.
