Q: how do I encrypt a folder for email

I have used BetterZip to handle most file compressions for Mac->Windows. It avoids carrying the hidden Mac files during compression. The newest version has strong encryption capabilities.

--
JJW

You cannot encrypt files or folders with OS X. What you can do is create an encrypted disk image and send that if the windoze-side can mount it.

First open the file on your computer.  Then go to file>print.  Click on the PDF button and then select save as PDF.  Select where to save it, then select security options.  Then save it and give it a password.  Now open Mail and create a new message and attach the password protected PDF.  When you attach the PDF a notice comes up that the PDF is password protected and it asks for the password.  Don't put in the password, just send the email.  The person receiving the email will have to put in the password to open it.  It works very well, even when receiving it on an iPad.

Use the command line Zip to do the compression and encryption. You'd have to do your own research on how to do it.

This is the version that is installed on Mountain Lion.

http://www.info-zip.org

You cannot encrypt a folder just like that. You can encrypt your folder through creating a disk image http://www.beencrypted.com/how-to-encrypt-mac-folder/ . After that you can email that encrypted .dmg file over the email.