How to password-protect a PDF before e-mailing in OS X

With a few steps you can set up an easy way to encrypt PDF files generated from the standard print dialog window.

Topher Kessler MacFixIt Editor
Topher, an avid Mac user for the past 15 years, has been a contributing author to MacFixIt since the spring of 2008. One of his passions is troubleshooting Mac problems and making the best use of Macs and Apple hardware at home and in the workplace.
Topher Kessler
2 min read

The print-to-PDF feature in OS X is convenient for quickly preserving a document's layout in the PDF format, so it can be viewed on most computers and tablets. If you would like to send someone a formatted document that contains sensitive information, you may want to add the step of protecting it with a password.

To do this, you can use a container format such as a ZIP file or an encrypted disk image (using the Disk Utility program in OS X); however, these may be a bit cumbersome to manage, both for the sender and recipient.

An alternative is to send the PDF as an encrypted PDF file with a password that must be entered by the recipient before the PDF can be read.

Encrypting PDFs in Preview
After choosing Print to PDF and opening in Preview, save the document and click the Encrypt option (circle). Then send the encrypted PDF using the Share button (arrow) as an e-mail attachment (click for larger view). Screenshot by Topher Kessler/CNET

There isn't a specific option to print a document to an encrypted PDF format in OS X, but the procedure is simple enough:

  1. Use the PDF menu in the print dialog box and choose "Open PDF in Preview."
  2. Press Command-S to save the PDF.
  3. In the save dialog box, click the "Encrypt" check box and provide a password for the PDF, and then save it to your desktop (or similar location).
  4. Now click the Sharing toolbar button in preview and choose the Email option.

This action will create the encrypted PDF and offers a relatively easy way to attach it to a new e-mail message. However, if you use this feature regularly then you may want a slightly more streamlined approach.

Luckily, OS X supports an option for custom print plug-in workflows that you can use to encrypt a PDF directly from the PDF menu in the print dialog window. To do this, open the Automator program (in the Applications folder) and follow these steps:

Encrypted PDF Print Plugin Automator workflow
When creating the workflow, for the encryption action be sure to check the option to show the action's input when the workflow runs (click for larger view). Screenshot by Topher Kessler/CNET

  1. Create a new workflow.
  2. Select "Print Plugin" as the type of workflow to create.
  3. Locate the "Encrypt PDF Documents" action and drag it to the workflow area.
  4. Click the Options button for this action and check the option to "Show this action when the workflow runs."
  5. Locate the "New Mail Message" action and drag it to the workflow, below the encryption action (you can optionally use the "Add Attachments to Front Message" action, or have this in a separate workflow altogether).

Save the workflow with a name like "Mail Encrypted PDF" and you should be good to go. Now whenever you print a document you can choose this workflow from the PDF menu and after you supply the password to use, the system will generate the secured PDF document in a new e-mail message.

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