Product Feature Sheets

white papers

White Papers

use cases

Use Cases

case studies

Case Studies

What's New Latest Release - W7.10

Outlook Add-in

This page provides an overview of the DeliverySlip Outlook add-in, including quick facts, system requirements, instructions on how to install and activate the add-in, and how to use it in Outlook.


The Secure Messaging Outlook Add-in allows internal and external users to manage their secure messages alongside their basic email messages seamlessly in the world’s most widely used corporate email program. Once installed, any authorized user can create, read, and respond to secure messages right in Outlook and to use all the powerful Secure Messaging functions available from the delivery slip that appears to the right of any secure message. This includes: easily requesting and providing legally valid e-signatures; sending and receiving large files without having to log into a cumbersome FTP server or a browser-based application with additional unsafe links to click; mounting and managing secure, trackable bulk send e-campaigns; using all of Secure Messaging’s sophisticated tracking and control tools. There is no need to navigate to a separate browser for sender and recipients.

Because there are no cumbersome security keys to exchange and manage for both sender and recipients, your organization can exchange confidential information with all stakeholders such as staff, clients, and partners in a complete secure closed-loop environment that is fully auditable.

There is no need to reconfigure mail server settings or change staff email addresses or ISP (e.g., MX records remain where they are) to use the secure Outlook add-in. It is designed to be a client-side solution where the add-in is easily installed in minutes without requiring administrative rights or training. Because it is a cloud-based solution that uses HTTPS rather than SMTP, secure messages can be sent through your organization’s branded secure messaging platform directly without having to interact with your mail servers. It works with all mail servers including Microsoft Office 365, Microsoft Exchange, Gmail, Yahoo! Mail and Zimbra without requiring complex integrations or expensive configurations. All existing investments in email archiving, compliance, e-discovery, workflow, and management remain intact and continue to work. No changes or replacements are required.


Quick Facts

  • Secure messages are sent through your organization’s branded Secure Messaging platform, and therefore, are secure throughout the exchange.
  • Designed to be a light-weight client-side solution easily installed in under two minutes without requiring administrative rights.
  • Because there is no new software to learn and it’s so simple to use, the solution will actually be supported and adopted by staff and external recipients, ensuring the encryption of your sensitive data.
  • Email content and file attachments can be stored decrypted in the mail server (e.g. Exchange) both by the sender and the external recipients without integration at the mail server level.
  • Eliminates the need for recipients to login to a separate mail store that, typically, is only available through a web browser.
  • Gives users the option to quickly choose between creating a new secure or basic email message.
  • The Delivery Slip is added to the right side of the compose window and gives you access to all of Secure Messaging’s powerful features.
  • Instantly and securely send, receive, and track attachments and e-signature documents without taxing the mail server.
  • It works with all mail servers and all existing email archiving, compliance, e-discovery, and DLP set-ups.
  • No server changes are required, making it a true cloud solution.


System Requirements

  • Microsoft Office Outlook 2013, 2016 & 2019 all editions.
  • Support for Group Policy Deployment available (MSI).
  • Support for Terminal Server / Citrix available (MSI).
NOTE: At this time, there is not a Secure Messaging Outlook add-in for the Mac version of Outlook. If you are on a Mac, please use the Secure Messaging desktop app or the web application.NOTE: The IMAP protocol is currently not supported by the Secure Messaging add-in for Outlook. This is because the IMAP protocol syncs message and attachment data between Outlook and your mail server unencrypted in plain text, thus allowing decrypted secure messages to be sent in the clear over the internet and saved unencrypted on the mail server. This constitutes a security breach. We recommend that you do not use IMAP with Secure Messaging added to Outlook. Please contact your administrator for more information or alternatives.

NOTE: The Secure Messaging add-in for Outlook is not supported in versions of Outlook that are installed from ‘Office in the Microsoft Store’.  Most importantly, these versions offer poor COM add-in support and in some cases, the COM add-ins are not supported at all.


Installation – Part One

  1. Go to and log in to your Secure Messaging account.
  2. From the left navigation panel, click any of the app icons.
  3. Click the Windows icon. (At this time, there is not a Secure Messaging add-in for the Mac version of Outlook.)
  4. Under Microsoft Office Add-in click Install now… (Notes: 1) If you do not see the ability to install the add-in from the Install Apps screen, it is not available for your Secure Messaging account; if you wish to use Secure Messaging in Outlook, contact your administrator for more information. 2) If you do not have the MS .NET Framework 4.0 installed on your computer, you will be prompted to install it. The installation is automatic and must be completed in order to use the add-in. The .NET Framework 4.0 is a Microsoft designed component and does not put your computer at any risk.)

Installation – Part Two

Once you click Install now…, a new page will load with the following instructions:

  1. Close Outlook.
  2. Download the add-in by clicking the Download button.
  3. Install the add-in: Click the downloaded file and follow the installation instructions.
  4. Activate the add-in in Outlook. (There are separate instructions for activating the add-in, below).



Once the installation of the Outlook add-in is complete, the next step is to activate it. Follow these steps to complete the activation and begin using the add-in:

  1. If the instruction window (above) isn’t still open, navigate back to it per the instructions above.
  2. If you haven’t done so yet, click the Activate button (Step 4 in Part Two, above). This will send a secure message to your email address.
  3. Launch Outlook.
  4. When Outlook first loads, select the new secure message you’ve received (it may automatically be selected for you). Alternatively, if you received a secure message notification from someone you know, please select it in your Outlook inbox.
  5. Once you select a secure message, you will see an activation screen, prompting you to enter your password (the image shown in Installation – Part Two, Step 4, above). Enter your password as selected when you registered with the secure messaging platform.
NOTE: If you are experiencing any issues with the secure Outlook add-in installation, please contact your administrator as there are scenarios that could prevent the add-in from establishing a secure connection with your version of Outlook. If you are experiencing problems loading the add-in, please see the troubleshooting tip ‘Secure Outlook Add-in Loading Issue’.


Using the Secure Messaging Add-in for Outlook

  1. Once you’re all set up with Secure Messaging in Outlook, your secure messages will appear inline with your basic email.
  2. To reply, reply all, or forward a secure message, simply click those options as you would normally. (To reply to or forward a basic email as a secure message, see Changing a Basic Email to a Secure Message, below.)
  3. To create a new secure message, click the New Secure button, from either the Home tab or the Secure Messaging toolbar tab.
  4. When you click on a secure message or launch a new secure message, the Delivery Slip will appear next to the message. (For all the options available to you in the Delivery Slip and how to use them, please see How to Use the Delivery Slip).
  5. To access the Secure Messaging toolbar, click the Secure Messaging tab. This will give you a number of options:
    • Secure Webmail: Click this to access your Secure Messaging account in the Secure Messaging webapp.
    • Preferences: Access your Secure Messaging options for the Outlook add-in. This includes choosing your default Secure Messaging account (if you have more than one). See Changing the Default Secure Messaging Platform, below, for more information. For an explanation of other Preferences options, see Managing Outlook Add-in Preferences, below.
    • Secure Accounts: See a list of your Secure Messaging accounts. If you need to delete a Secure Messaging account, you do so here. Instructions for that are provided under “How do I remove my account activation” on the Account Management FAQs page.
    • Check for Updates: Click this to see if a new version of the Outlook add-in is available.
    • Report an Error: If you notice anything wrong with the Outlook add-in, please click this and report your issue.
    • Help: Provides access to Secure Messaging online help as well as what’s new with Secure Messaging, policies, and other information.


Changing a Basic Email to a Secure Message

You can easily reply or forward a basic email message and convert it into a secure message (e.g. you do not have to start a new secure message in order to send it via your Secure Messaging account).

  1. To convert an email to a secure message, simply click to reply to or forward the basic message as you would normally.
  2. Then, from the Delivery Slip, select Click here to change delivery options and select a Secure Messaging platform. This will send your reply as a secure message and will include the original thread of this conversation.
  3. If you do not wish to see this pane expanded the next time you create, reply or forward a basic email message, check the Hide Delivery Slip when creating new basic email messages option to automatically keep the pane collapsed.
NOTE: You cannot do the reverse and convert a secure message to a basic email message, as this would defeat the purpose of the Secure Messaging platform.


Recalling a Secure Message in Outlook

Professional users have the ability to recall a secure message even if recipients have already read it. Recalling a secure message in Outlook is as simple as selecting the message in your sent items, and clicking the Recall Message button located at the top of the Delivery Slip.

You will be given the opportunity to enter a reason for the message recall. This will be displayed to all recipients that attempt to access the recalled message. If you do not enter a reason, default text will be displayed. Recalling a message prevents recipients from viewing the content, replying to it, or forwarding it. The message will be revoked the next time they try to access it. In addition, all file attachments will no longer be available to recipients.

  1. Click the Recall button in the Delivery Slip to recall a secure message at any time.
  2. Optionally, enter a reason for recalling the secure message that will be displayed to all recipients.


Secure Message Recalled

If the secure message you selected has been recalled by the owner, you will no longer be able to read, reply to, forward or print it.

  1. The Delivery Slip’s Message Details now shows all tracking related metadata as Recalled.
  2. The Message Status is changed from Active to Recalled.
  3. Access to the secure message and its associated file attachments is no longer available. The owner of the recalled secure message might have included a reason for recalling the message, available in the body of the message.


Managing Outlook Add-in Preferences

Outlook add-in references are accessed via the Secure Messaging toolbar tab.

  1. If you registered with more than one Secure Messaging platform, you can select which one should be used by default for all new secure messages. This setting will not prevent you from choosing a different Secure Messaging platform on a per message basis.
  2. Set which browser to use when you opt to launch the Secure Messaging webapp from within Outlook.
  3. The Secure Messages section allows you to set several options:
    • Select whether secure messages should be auto-retrieved (automatically decrypted) once you select them in your inbox, or if each secure message should be retrieved manually (by using the Retrieve button in the Delivery Slip).
    • To save real estate on your screen, you may not want to have the Delivery Slip expand when composing new, basic (unsecure) messages. If so, select Hide Delivery Options to keep the Delivery Slip collapsed.
    • Select the Enable Send Secure button to have it available when composing a new email message.
  4. Since Secure Messaging offers better and more accurate message tracking, the Toolbar will automatically ignore the Read Receipt options you had previously set in Outlook as they are not required with secure messages (on by default, cannot be changed). Read Receipt options will still be upheld for basic (unsecure) messages.
  5. When first installing the Toolbar, some Did You Know tooltips are displayed to help the user navigate the new features available. To turn those off, select this option. To re-enable them and see all tooltips again, click on the Reset Tooltips button.
  6. Some versions of Outlook sometimes display a false error message when using the add-in. To not see these warning messages, select this option (off by default).


Changing the Default Secure Messaging Platform

If you communicate with more than one secure messaging platform, the add-in will display all of them as a selection when composing a new secure message. As noted above, to change the default secure messaging platform in Outlook, go to the Secure Messaging tab and click on Preferences. At the top of the preferences window there will be an option for Default Secure Messaging Platform. Choose the platform you want from the drop-down list and then click OK. This is now your default platform that will be used to send secure messages, unless you specifically choose a different secure messaging platform when composing a new secure message. You will notice that this secure messaging platform is now your default in both the “New Secure” and “Secure Webmail” buttons.


Enabling and Disabling Secure Messaging Accounts

If you have multiple Secure Messaging account activations using different email addresses, you may wish to block one or more of the secure accounts at some point in time.

The easiest way to block a Secure Messaging account is to select a secure message that was received using that account. Then, from the top of the Delivery Slip, click the down arrow next to the icons and click Block this secure account.

To unblock an account, click the Unblock button that appears in the Delivery Slip of a message sent to the blocked email address. Blocking and unblocking settings can also be accessed by clicking Secure Accounts on the Secure Messaging tab.

Why would you block a secure messaging account?

You may not want secure messages to automatically download into Outlook or you may not want to use particular email address’s activations any longer.

Sometimes a Secure Messaging platform will block an account, and you will not be able to unblock it. This occurs, for example, when the Secure Messaging platform determines that you no longer own the email address associated with an account. If you cannot unblock an account and you feel that there has been a mistake, please contact your administrator to request help with the issue.


Sending a message with Challenge Response Authentication (CRA)

When Challenge Response Authentication (CRA) is enabled on the Secure Messaging Platform, every new User that you invite (e.g. communicate with for the first time) must enter a unique verification code in order to complete the registration. As a sender, in order to send a secure message to this recipient, you must enter this verification code in the form of a Member ID / PIN, Zip Code, Account Number, etc. Every organization has different rules regarding the secret code, if you are unsure, please contact your administrator.


Group Policy / Citrix / Terminal Server Deployments

If the secure email Outlook add-in was installed on your behalf by your administrator, you should receive a secure message to register with a secure messaging platform. Once you select the secure message, you will see the Registration & Activation screen, prompting you to enter your first and last name as well as to select a new password. This password is unique to your secure account and will not be used to access your primary email account.


Check for Outlook Add-in Updates

The latest version of the Outlook add-in contains the most up-to-date feature set, the latest bug fixes and updates, as well as the newest user experience upgrades. To get the latest version, follow these quick and easy steps:

NOTE: If you do not see this option in Outlook, please contact your administrator. The add-in was most likely deployed via a server system (Terminal Services / Citrix) and your administrator will perform the update on your behalf.

Outlook 2013, 2016 & 2019

  1. In the main Outlook window, go to the Secure Messaging or DeliverySlip tab.
  2. Click Check for Updates in the sub menu. If a new version is available, the dialog box will ask you if you wish to install it. Click yes, and follow the on-screen instructions to complete the update process. A dialog box will appear once the update is complete, after which you can restart Outlook.

If you do not see the “Check for Updates” menu entry, the add-in was installed remotely by your IT department using the Group Policy Deployment installation process. In this case, your administrator will install any updates for you.


Reporting an Error

If you encounter an issue using the Secure Messaging Outlook add-in, the best way to let us know is to use the Report an Error feature directly embedded in the add-in.

NOTE: You can submit an error at any time, even after the issue occurred. The logs included in the error report will include all the information we need.

Outlook 2013, 2016 & 2019

  1. Go to the Secure Messaging toolbar tab.
  2. Click Report an Error. A dialog will appear where you can enter a description of the problem that will be sent along with an encrypted copy of the log information from the add-in.

A support technician will contact you shortly to address your issue.


Uninstalling the Outlook Add-in

Should you need to uninstall the Outlook add-in for any reason, you should do this through the Add/Remove Programs interface included in Windows.

Step-by-step instructions for removing the Outlook add-in are provided below:

  1. Close Outlook.
  2. Open the Windows Start menu and go to Control Panel.
  3. In Windows XP, click Add/Remove Programs. For Windows Vista, Windows 7, and Windows 8, and Windows 10 go to Uninstall a Program.
  4. Select Secure MS Outlook Toolbar and click Remove (or Uninstall).

If you have uninstalled the add-in, but it remains visible in Outlook, please follow these steps:

  1. In Outlook 2007, click Tools > Trust Center. Select the Add-ins tab and select Manage COM Add-ins and click Go. Select Secure MS Outlook Toolbar, then click Remove.
  2. In Outlook 2010 and above, click File > Options. Select the Add-ins tab and select Manage: COM Add-ins and click Go. Select Secure Messaging Office Add-in, then click Remove.
  3. If you do not see the ability to uninstall the Outlook add-in, it was installed remotely by your IT Department using the Group Policy Deployment installation process. In this case, your administrator will have to uninstall it for you.

Last updated April 28, 2021


Does this work with Google, Office365 or Outlook?

Yes. DeliverySlip works equally well with Gmail/G Suite, Microsoft 365 and Outlook.

Do I need a new Email Account? Will there be Secondary passwords, PINS & keys to manage?

No, keep using your existing email address or aliases. Your email client and server infrastructure also remain the same. DeliverySlip works seamlessly from your inbox by using our Secure MS Outlook Toolbar or Chrome extension. There are no secondary passwords, PINS or keys required.

Where is the data stored when the email is sent securely?

Secure message content is stored encrypted at rest, using AES 256 bit encryption. Your encrypted data is stored in Microsoft Azure's cloud in the data jurisdiction that you selected (either USA, UK, Canada or Australia) upon your registration.

Do your support SSO (Single Sign On)?

DeliverySlip supports Azure Active Directory, Okta, Google, and others.

Does DeliverySlip work on mobile phones? Will I be able to read secure emails on a mobile phone?

Yes, DeliverySlip works on mobile phones and you will be able to read and reply to secure messages. Apps are available for iOS and Android devices.

Can email be automatically encrypted or must we manually encrypt it?

Yes. With data-leak prevention (DLP) rules enabled, DeliverySlip automatically encrypts information like Social Security, credit card or account numbers and keywords that can be tailored to your organization.

What regulatory compliance schemas do you support?

DeliverySlip is suitable for use with organizations that are subject to any number of regulatory compliance schemas including; GDPR, SOX, GBLA, FINRA and more.

Do you support “local store” for on premise Outlook Exchange?

Yes, local store for Outlook Exchange is supported. With this feature enabled, secure message content is stored locally in Outlook after you view the secure message, and then synced to Exchange.

Don't see your question here?

Check out our resource center for a full FAQ listing or complete our contact us form.

    How would you like to hear from us?

    Try it Now

    Your Secure Community portal is under construction. You will be redirected to your new portal shortly.

    creating portal