Gmail has a handy feature whereby, after hitting the 'Send' button, you have some time to realise you made a typo, forgot to attach a document or that you really don't want to send that message after all–or at least, not to the person you accidentally put in the 'To:' field.
This can be simulated in Outlook:
If you use Microsoft Exchange Server, you can delay delivery of an individual message. Everyone can use rules to delay delivery of all messages by having them held in the Outbox for a specified time after clicking Send.
Delay delivery of a message
- In the message, click Options.
- Under Delivery options, select the Do not deliver before check box, and then click the delivery date and time you want.
Delay delivery of all messages
- On the Tools menu, click Rules and Alerts, and then click New Rule.
- Select Start from a blank rule.
- In the Step 1: Select when messages should be checked box, click Check messages after sending, and then click Next.
In the Step 1: Select condition(s) list, select any options you want, and then click Next.
If you do not select any check boxes, a confirmation dialog box appears. Clicking Yes applies this rule to all messages you send.
- In the Step 1: Select action(s) list, select defer delivery by a number of minutes. Delivery can be delayed up to two hours.
- In the Step 2: Edit the rule description (click on an underlined value) box, click the underlined phrase a number of and enter the number of minutes you want messages held before sending.
- Click OK, and then click Next.
- Select any exceptions, and then click Next.
- In the Step 1: Specify a name for this rule box, type a name for the rule.
- Click Finish.
Source (shamefully copied from)