Preventing data breaches via Outlook

We all send so many emails that data breaches occurring via email are common. This article offers hints and tips for safeguarding against human error while using Microsoft Outlook, making use of existing features.

Turn off autocomplete when adding recipients
Delay or schedule sending email messages
Recall an email that you have sent
Show the Bcc (blind carbon copy) field
Enable ‘Do Not Forward’
Encrypt an email
Flag external emails

Turn off autocomplete when adding recipients

If you are concerned about accidentally emailing the wrong person from your address book, you may choose to turn off the autocomplete feature. This will prevent the dropdown that appears when you begin typing in the To, Cc and Bcc fields in a new email.

If you are using Outlook desktop client, take the following steps:

Select File, then Options
Select the Mail tab from the left-hand pane, and then click the Editor Options button
Click the Advanced tab from the left-hand pane, and then click to clear the check mark from the checkbox labelled Show AutoComplete Suggestions
Click Ok

For more information, and for instructions for Outlook on the web, see here.

Delay or schedule sending email messages

This feature can be helpful in giving you an extra moment to consider the content and recipients of your email even after you have hit send. If you want to stop the email going out, you will be able to cancel the send from your outbox.

The below instructions relate to Outlook desktop client. If you are using Outlook on the web, please see the link at the end of this item.

You can apply the delay either to messages individually or as a blanket rule for all your emails.

To add a delay to all emails you send:

Select File, then Manage Rules & Alerts
In the window that appears, select New Rule…
In the window that appears, select Apply rule on messages I send, then click Next
Select the conditions for which emails you want to delay, or to apply the rule to all emails simply click Next and then Yes to the pop-up alert
In Step 1, tick the checkbox next to the option to defer delivery by a number of minutes
In Step 2, click the blue underlined “a number of” text to confirm how many minutes you would like to add as a delay
Click Ok, then Next
Add exceptions if desired; otherwise click Next
Add a name for your rule so you can easily find it later, then click Finish

To delay the delivery of an individual message:

Select the Options tab in the window of a new email, and then Delay Delivery
In the window that appears, edit the Do not deliver before option with your desired timings

For more information, and for instructions for Outlook on the web, see here.

Recall an email that you have sent

In some circumstances, you may be able to recall a send message and prevent it from being read.

Find the email in your Sent Items folder
Double-click the message to open it
Select Actions, then Recall This Message...
Select Delete unread copies of this message or Delete unread copies and replace with a new message, and then click Ok
After submitting a recall request, you will get an email notification with the subject Message Recall Report for message. You can use this to check whether your message was successfully recalled.

For more information, and for instructions for Outlook on the web, see here.

Show the Bcc (blind carbon copy) field

The Bcc feature is useful to prevent sharing email addresses when sending mass emails. Email addresses entered in the Bcc field of an email will receive a copy of the email without their email being visible to the other recipients.

If you cannot currently see the Bcc field when composing an email, follow these steps to view it:

Create a new email or reply to or forward an existing one
If the new email appears in the reading pane, select Show Fields, then Bcc. If it opens in a new window, select the Options tab, then Bcc.

For more information, and for instructions for Outlook on the web, see here.

Enable ‘Do Not Forward’

This prevents recipients from having the ability to forward, copy, or print the email. This feature is particularly useful for controlling the distribution of sensitive information, ensuring that content stays within the intended audience.

For more information see here.

Encrypt an email

All emails in Exchange Online are already protected with TLS encryption, ensuring secure transmission. The "Encrypt" feature in Outlook provides an additional layer of security by encrypting the email content itself. This ensures that only the intended recipient can view the message, making it particularly important for sharing sensitive information.

For more information see here.

Flag external emails

Microsoft has introduced an ‘External’ tag to flag when emails are being sent to, or received from, email addresses outside of the organisation. This feature is automatic and there is nothing you need to do in order to enable it.

Knowing when an email is being sent externally provides a useful reminder that certain information ought not to be shared outside of Teach First. It can also flag where you might have accidentally selected the wrong email address, if you intended to send the email internally.

The feature also shows you when emails you have received have come from an external source: