How to Send a Folder by Email: Step-by-Step Guide
8 October 2026
You cannot attach a folder to an email the way you attach a file. Mail clients accept individual files only,
so the fix is to compress the folder into a single zip file and attach that, or send it as a
link when the folder is too big for your provider's cap.
Knowing how to send a folder by email matters most when the contents need to land intact, with the subfolders
and file names the recipient expects. A zip holds that structure together in one attachment. It also saves
the recipient from rebuilding a project out of eleven loose files.
Here are the steps for Windows, Mac and mobile, the size limits that decide whether your zip ever leaves the
outbox, and the safer route when a folder is far too big to attach.
How to Send a Folder by Email in Four Steps
Compress the folder into a zip, attach that zip to a new message, tell the recipient what is inside, then send. Zipping is the step people miss, because every mail client treats a folder as something it cannot attach and a zip as an ordinary file.
- Tidy the folder first. Delete drafts, duplicates and stray exports. Smaller and cleaner is often the difference between a send and a bounce.
- Compress it. Right-click the folder, choose your system's compress command, and a .zip file appears next to the original.
- Check the size of the zip, not the folder. Compression results vary wildly by file type, so trust the number on the archive.
- Attach and explain. Drag the .zip into the message and name what is inside and how many files, so the recipient can tell whether the download arrived complete.
Name the zip something the recipient will recognise months later. A file called Archive.zip sitting in a client's downloads folder tells them nothing.
Zip a Folder on Windows, Mac or Mobile
Every current operating system zips a folder without extra software. Right-click the folder, choose the compress command, and a .zip appears beside the original. Nothing is moved or deleted, so the folder you started with stays exactly where it was.
Zip a Folder on Windows 11 and Windows 10
Windows builds the zip through File Explorer in two clicks, though the menu wording changed between versions.
- Windows 11. Right-click the folder, hover over Compress to, then choose ZIP file.
- Windows 10. Right-click the folder, hover over Send to, then choose Compressed (zipped) folder.
- Either way, type a new name while the file is still highlighted and press Enter.
Windows 11 keeps the older Send to route under Show more options, which helps when a device is mid-upgrade and the menus look unfamiliar.
Zip a Folder on macOS
Control-click the folder in Finder and choose Compress from the shortcut menu. Apple's guide to zipping files and folders on Mac sets out the naming behaviour, which catches people out more often than the compression itself.
Compress one folder and the zip takes that folder's name. Select several items and compress them together and macOS calls the result Archive.zip instead, so rename it before attaching.
Zip a Folder on iPhone or iPad
Open the Files app, tap Select, choose the folder, then tap the More button and Compress. The .zip lands in the same location, ready to attach from your mail app.
Touch and hold the new archive to rename it. Mobile is fine for a handful of documents and painful for anything large, since the upload runs on whatever connection you happen to be on.
Check Email Attachment Size Limits Before You Attach the Zip
Most failed sends come down to one number. Personal Gmail caps attachments at 25 MB per message, and Outlook on the desktop defaults to 20 MB for internet email accounts. Your zip has to clear your cap and the recipient's cap to arrive.
| Email account | Default attachment limit | What happens above it |
|---|---|---|
| Gmail, personal account | 25 MB per message | Gmail strips the files out and inserts a Google Drive link |
| Outlook desktop, internet email account | 20 MB per message | Outlook blocks the send and shows a size error |
| Exchange Server mailbox | 10 MB per message | Blocked unless an administrator raises the limit |
Microsoft documents that attachment size error in Outlook and the registry change some IT teams use to lift the desktop limit, though the mail server still has the final say.
Two things make those caps tighter than they look. Attachments are encoded for transit, which inflates them by roughly a third, so a 22 MB zip can fail against a 25 MB limit. The recipient's mail server then applies its own ceiling, often lower than yours.
Why Zipped Folders Get Blocked or Bounced
A zip can sit well under the size limit and still never arrive. Providers inspect what is inside the archive, and one risky file type rejects the whole message. Locking the zip with a password makes that worse rather than better.
- Executable and script types are blocked even inside a .zip, so one stray .exe, .js or .msi stops the send.
- Password-protected archives that hide their contents from scanning are blocked too, which surprises people who added the password for safety.
- Corporate mail filters often quarantine archives by policy, so the message vanishes quietly rather than bouncing.
- Zipping rarely shrinks video, photos or audio, because those formats are already compressed. A 3 GB video folder stays close to 3 GB.
Google's list of file types blocked in Gmail is the fastest way to check a folder before you compress it, and it is worth a look before any developer handover.
Send a Folder That Is Too Big to Attach
Send a link instead of an attachment. The folder uploads once, the recipient downloads it from a URL, and no mail server in between has to carry a 4 GB archive. This is the normal route for video, photography, design files and full project handovers.
| Zip as an attachment | Folder sent as a link | |
|---|---|---|
| Practical size | Under about 20 MB | Gigabytes |
| Recipient effort | Download and extract | One click to download |
| Delivery proof | None | Download alerts on most services |
| Fails when | Size or file type is blocked | Rarely |
Cloud storage links work, with one catch. Drive and OneDrive links often prompt the recipient to sign in or request access, which turns a handover into an email thread.
A purpose-built transfer tool skips that step, and you can send large folders as a secure link with up to 10 GB per transfer on the free plan and no account needed at the other end. Upload the zip rather than loose files and your subfolders reach the client exactly as you arranged them.
Protect Client Folders Before You Send Them
Treat a zipped folder as an unlocked box. Compression is not encryption, and anyone who intercepts or is forwarded the attachment can open it. Contracts, personal data and client work need controls that travel with the file, not just a smaller file size.
Three controls do most of the work.
- Password protection. Set it on the transfer rather than on the archive, then share the password separately. Our guide to password protected files covers how to split the two safely.
- Link expiry. Time-limited access stops a folder of client data sitting in someone's inbox for two years.
- Encryption in transit. TLS 1.3 protects the upload and the download, which a plain attachment cannot promise across every hop.
Where the files sit matters as much as how they travel. If you handle personal data for Irish or EU clients, EU-hosted infrastructure and a documented GDPR compliant file transfer process keep your obligations simple to evidence.
Sending a folder is really two decisions. Zip it and attach it when the contents are small, ordinary documents. Send it as a controlled link when the folder is large, sensitive, or going to a client who will judge you on how the delivery looked.
Compress the folder, check the zip against the caps above, and switch to a secure transfer link the moment the number goes past them.
Frequently Asked Questions
Can you attach a folder to an email without zipping it?
No. Mail clients accept files only, so a folder has to be compressed into a zip first or uploaded and shared as a link. Drag a folder into a webmail window and it either uploads the contents loose or does nothing.
How do I send a folder through email from my phone?
On iPhone and iPad, use Select and Compress in the Files app, then attach the .zip from your mail app. Android varies by device, so if your file manager has no compress option, upload the folder to a transfer service instead.
What size folder can I send by email?
Personal Gmail allows 25 MB per message and desktop Outlook defaults to 20 MB for internet email accounts. Encoding inflates attachments by about a third, so aim well below the cap or send a link.
Does zipping a folder make it smaller?
Sometimes. Documents, spreadsheets and design source files compress well. Video, photos and audio are already compressed, so a zipped media folder usually ends up close to its original size.
Why was my zip file blocked?
Providers scan inside archives. One executable or script file, such as an .exe or .js, is enough to block the whole message, and archives locked with a password are often rejected because their contents cannot be scanned.
Is it safe to email a zipped folder of client data?
Not on its own. A zip is not encrypted, and the attachment stays in both mailboxes indefinitely. Personal or contractual data is safer sent through a service with encryption in transit, access controls and link expiry.