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How to Zip Attachments

Note: Some options described here may be mandated or disabled by Smartcrypt Policy. Contact your Smartcrypt Policy Administrator for more information.

To zip attachments with Smartcrypt Attachments, go to the Smartcrypt tab on the toolbar of the new message window, then click Enable  to turn on zipping before you send your message. The attachments are zipped using the options you have set.

Use the Outlook toolbar buttons (described below) or the context menu of the Smartcrypt Attachments tool tray icon to turn zipping and related options On or Off.

To zip and mail an attachment:

  1. Open a message window in Outlook by starting a new message or replying to another message.
  2. Attach file(s) as you usually do.
  3. Confirm that options to Compress, Encrypt and/or Sign attachments are set the way you want them. Click any toolbar option to turn that option on or off.
  4. Click Send.

The attachments are zipped using the settings for configuring compression, encryption, and signing selected in Smartcrypt Options.

If attachments are to be encrypted, prompts to specify a passphrase and/or recipient list appear as needed.

Depending on how your policy is set, you may get an additional prompt to encrypt files or other sensitive data when emailing to people outside your organization. Follow the instructions at the top of the External Recipient and Content Validation screen to proceed.

Note: If you have selected the Mail option in Smartcrypt to Auto-search for recipients, when you send a message with a zipped attachment, a Microsoft Outlook warning dialog may open to display a message that a program is trying to access email addresses you have stored in Outlook. The dialog asks if you want to allow this.

It is normal for this dialog to appear if you are encrypting an attachment with a recipient list. In the dialog, check the Allow access for 1 minute box and click Yes to proceed.

The recipient of the message can double-click the zipped attachment to open it in Smartcrypt or whatever other program is set up to work with .ZIP files. (If the contents of the ZIP file are encrypted, the recipient may need Smartcrypt or ZIP Reader to decrypt and extract the files.)

Caution: When using certificate-based encryption to email files to multiple individuals, be aware that recipients may be able to identify if blind copies (bcc) of the message was sent. If the message body is encrypted, the certificate information of all recipients (including those recipients in the bcc field) are decrypted.

How the ZIP Archive Is Named

  • If the ZIP archive contains multiple files or if the option Encrypt file names is on, the file is given the name specified in the Default ZIP name option (on the General page of Mail options). With a single file attachment, the ZIP file is ordinarily named after the attached file. For example, if the file is vital_info.doc, the ZIP archive attached to your message is named

  • If the message body is encrypted, then all of the attachments and the message body are converted to one MIME-format .eml file, and this file is encrypted and zipped. The names of the .eml and ZIP files are based on the subject of the message plus a timestamp: for example, My message subject 2009-10-05 14_19_27.EML.

Default Settings for the Outlook Toolbar Buttons

When you open a window in Outlook to compose a message, the initial On/Off settings of the Smartcrypt Attachments toolbar buttons are determined by check box settings in Smartcrypt Options (on the General page of the Mail category in Smartcrypt). The check boxes establish the default settings for the buttons. The toolbar button opens Smartcrypt Options.

In Outlook, you can tell from the appearance of the Encrypt body, Encrypt attachments and Sign toolbar buttons what their default settings are. You can also change the defaults from the buttons:

  • If zipping attachments is on (in other words, the Compress attachments button is selected): Selecting or deselecting the Encrypt or Sign button also changes the corresponding default setting in Smartcrypt Options.

  • If the Encrypt or Sign button is selected when you turn zipping Off: Turning off zipping when encryption or signing is set On adds an x in a tiny red circle to the respective button (see the table below). This tells you that the option will be On when you turn on zipping.



What It Means


Encrypt attachments

Encrypting is set On by default and will be enabled when you turn on zipping


Sign attachments

Signing is set On by default and will be enabled when you turn on zipping

Set Outlook Toolbar Buttons to Encrypt or Sign

The message window in Outlook (and Word, when used as a mail editor) also has buttons to turn on encrypting or signing when attachments are zipped. These buttons appear in the same location as the ZIP button described above.

For example, if the Encrypt button is selected when you zip attachments, attachments are encrypted when they are zipped. (You can zip attachments without encrypting or signing them, but you can only encrypt or sign attachments when you zip them.)


Corresponding Tool Tray Setting

Encrypt body (and attachments)


Encrypt attachments


Sign attachments

Skip actions

Note: If Encrypt message body is set, the message body is encrypted too when you encrypt attachments.

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