Outlook can’t attach a folder directly; if you try to drag one into a message, nothing happens or you get an error. To send a folder’s contents, you either compress it into a ZIP file and attach that, or share it as a OneDrive (or other cloud) link, which also gets around attachment size limits. This guide covers both methods in Outlook for Windows (classic and new), Outlook on the web, and Outlook for Mac.
Quick Answer
In File Explorer, right-click the folder and choose Send to > Compressed (zipped) folder (or Compress to > ZIP File in Windows 11). Then in Outlook, create a message, click Attach File > Browse This PC, and select the ZIP file.
Method 1: Zip the Folder and Attach It
- Open File Explorer and find the folder.
- Right-click it and choose Send to > Compressed (zipped) folder (Windows 10) or Compress to > ZIP File (Windows 11).
- A .zip file with the same name appears next to the folder.
- In Outlook, click New Email.
- Click Attach File > Browse This PC (or drag the ZIP file into the message).
- Add recipients, a subject and a message, then click Send.
Recipients right-click the ZIP and choose Extract All to open the folder.
Method 2: Share the Folder With OneDrive
Best for large folders or when you want recipients to always see the latest files.
- Move or copy the folder into your OneDrive folder (or upload it at onedrive.com).
- In Outlook, click Attach File > Browse cloud locations (or Upload and share) and choose the folder or ZIP.
- Or right-click the folder in File Explorer, choose Share, set permissions (view or edit), and copy the link into your email.
Other services like Google Drive and Dropbox work the same way: share a link and paste it in the email.
Attachment Size Limits
- Outlook with Microsoft 365 or Outlook.com typically allows attachments up to about 20–25 MB (organizations can set different limits).
- The recipient’s email provider may have a lower limit.
- For anything larger, use a OneDrive link, which can share files of many gigabytes.
Outlook for Mac and the Web
- Mac: in Finder, Control-click the folder and choose Compress. Attach the ZIP with the paperclip icon.
- Outlook on the web: click Attach and choose Browse this computer for a ZIP, or Upload and share to put it in OneDrive and send a link.
Troubleshooting
- “Attachment size exceeds the allowable limit”: use a cloud link or split the folder into smaller ZIPs.
- ZIP blocked by recipient: some organizations block ZIPs containing executables (.exe, .bat). Share via a cloud link instead.
- Can’t drag a folder into Outlook: that’s expected; zip it first.
Frequently Asked Questions
Can I password-protect the ZIP?
Not with Windows’ built-in tool. Use 7-Zip to create an encrypted ZIP, and send the password separately (for example by text).
Does zipping reduce file size?
Documents shrink a lot; photos, videos and PDFs barely shrink because they’re already compressed.
Can I send a folder of emails?
Select the emails, forward them as attachments, or export the folder to a .pst file via File > Open & Export > Import/Export in classic Outlook.
Summary
- Zip the folder in File Explorer.
- Attach the ZIP to an Outlook message.
- Or share the folder with a OneDrive link.
- Use links for anything over about 20 MB.
Kermit Matthews is a freelance writer based in Philadelphia, Pennsylvania with more than a decade of experience writing technology guides. He has a Bachelor’s and Master’s degree in Computer Science and has spent much of his professional career in IT management.
He specializes in writing content about iPhones, Android devices, Microsoft Office, and many other popular applications and devices.