How to Encrypt Email Communication for Free

CryptWit - Free email encryption for Outlook

cryptwit softwareCryptWit is designed to resolve two major flaws of email communication.
Email transport is almost always based on plain text, which makes it completely insecure. The other problem is that most email providers block large attachments.

CryptWit makes email more secure by encrypting message body as well as attachments.

How does it work? It utilizes ZIP compression to reduce total size of email message thus allowing more data through limited email communication channels and it encrypts the contents at the same time.

Email encryption

CryptWit encrypts message contents as well as attachments. Email encryption prevents electronic mail from being read by an unintended recipient and from being scanned and filtered by software sniffers. Even if it is intercepted or copied, the message will stay encrypted unless the recipient has the key.

Email compression

CryptWit compresses message contents and attachments. Data compression makes the CryptWit message up to 80% smaller than the original message by using lossless compression algorithms, originally developed by Phil Katz from PKWare and later acquired by IBM. This allows sending more data in one transmission without using large file transfer services.
Subsequent encryption is performed by the Ionic Zip library owned by Microsoft.

Anyone can use it

Your recipients do not need CryptWit to read encrypted message. Any email recipient can receive secure communication from CryptWit. To decrypt and read it they'll only need a password. No special software is needed on the recipient's computer. In fact, emails sent by CryptWit are delivered via Hotmail, Yahoo, Gmail, and other free email services perfectly.

Portable message format

The complete portability of the message format is what makes CryptWit great. CryptWit archives your outbound email message into an Enrypted ZIP file before sending. Most of the modern computers and mobile devices support ZIP files right out of the box.

Large attachments

CryptWit supports up to 20MB of file attachments to be sent in a single encrypted ZIP file. If the original message contains more data, it is recommended to split it into multiple submissions, or use a file transfer service such as Sometimes there is an advantage in using large file transfer services, as they often provide advanced file handling, detailed tracking, and delivery confirmation.

What is CryptWit?

CryptWit is a free add-in for Microsoft Outlook for Windows. Upon the first use, it prompts to enter the new password for email communication. Other configuration settings such as compression level and encryption strength come pre-set to provide optimal performance figures. By default, the password to the archive is never sent to the recipients in the same message, as this would neutralize the security of the email communication. The password should be kept separate from the encrypted message.

Certified Install

The product setup package and the plug-in come digitally signed with a secure electronic certificate from Pixel Transitions, LLC and verified by Godaddy, Inc. If you have acquired CryptWit without the digital certificate, do not install it. Instead, please contact Pixel Transitions, LLC for a free certified copy of the software at, or via regular mail to PO Box 48196 Tampa, FL 33646, USA.

Software Requirements

  1. License: Free for personal use
  2. OS: Windows 7 thru Windows 10
  3. Platform: 32-bit or 64-bit
  4. Microsoft Outlook version 2010,2013,2016, 365 Desktop, 2019
  5. .NET Framework 4.0 or newer

* For Office 2013-2019 use the Full Setup Package which includes Office InterOp DLLs. Contact us with any questions.

Free support

CryptWit is developed by Pixel Transitions, LLC and is free for personal use. With any questions about the product, including its distribution or support, please contact us at To license the product for corporate use please contact us via