How to Send a ZIP Archive via Email

You've compressed everything into a ZIP — multiple files, neatly packaged — and the archive is 45MB. Gmail still rejects it. Outlook still bounces it. Compressing an already-compressed file doesn't make it smaller. And most files inside (JPEG, MP4, PDF) don't compress much anyway. The ZIP is just as large as the contents.

SendSplit accepts your ZIP, splits it into numbered ZIP parts, and delivers each as a standard email attachment. The recipient downloads all parts, reassembles the ZIP, and extracts your original files — intact, no quality loss, no re-compression.

Why Compressing Files Doesn't Always Help

Many people create a ZIP hoping to shrink a file below email limits. This works well for text files and documents — but most file types people actually need to send are already compressed at the format level:

  • JPEG images — already compressed; a ZIP of JPEGs is nearly the same size as the originals
  • MP4 / MOV video — H.264 and H.265 are highly compressed formats; zipping achieves almost nothing
  • PDF files — typically well-compressed internally; ZIP adds less than 5% savings
  • PNG images — already use lossless compression; ZIP of PNGs barely shrinks at all
  • Office files (XLSX, DOCX, PPTX) — these are already ZIP archives internally; adding another ZIP layer gives negligible savings

If your ZIP is still too large for email after compression, the solution isn't to compress harder — it's to split and deliver differently.

What Happens When You Send a Large ZIP with SendSplit

SendSplit takes your uploaded ZIP and splits it into numbered ZIP parts for email delivery. The output is always ZIP format, which means the recipient only needs standard built-in tools to open the parts. Here's what happens on both sides:

Sender side:

  1. Upload your ZIP to sendsplit.com/upload-to-send (up to 200MB)
  2. Choose a split size: 10MB, 20MB, or 25MB
  3. Enter the recipient's email and click send

Recipient side:

  1. Receives a series of emails, each with a numbered ZIP part (e.g., archive.zip.001, archive.zip.002)
  2. Downloads all parts into the same folder
  3. Opens the first part (.001) with any archive tool — 7-Zip, WinRAR, macOS Archive Utility, or Windows Explorer — which automatically reassembles the split ZIP
  4. Extracts the original file contents — all files, original quality, nothing missing

Because SendSplit always outputs ZIP format parts, the recipient does not need WinRAR or any paid software — free tools like 7-Zip (Windows) and the built-in Archive Utility (macOS) handle split ZIPs natively.

Email Filters and ZIP Attachments

Some email security gateways are suspicious of ZIP files because malware is sometimes distributed in archives. If your recipient reports that the split parts were quarantined or flagged:

  • Ask them to check their spam or quarantine folder
  • Try sending with password protection — encrypted ZIPs cannot be scanned by content filters, which paradoxically makes them more likely to be passed through by some gateway configurations
  • Alternatively, contact the recipient's IT department and ask them to whitelist your sending address

Tips for Sending ZIP Archives via Email

  • Name your archive clearly — ProjectName_Files_2025.zip is better than archive.zip; the recipient will see the filename in every split email
  • Use 10MB splits for corporate recipients — corporate email servers are often capped at 10MB per incoming message; 10MB is the safest universal setting
  • Test with a small file first — if you're unsure whether the recipient's server will accept split ZIP parts, send a small test file first to confirm delivery
  • Add password protection for sensitive archives — enable SendSplit's optional encryption for any archive containing confidential documents, personal data, or proprietary files

Stop trying to compress files that are already as small as they'll get. Try SendSplit — split your ZIP into email-friendly parts and deliver them as standard attachments to any inbox, up to 200MB, no accounts required.