Get someone’s attention with @mentions in Outlook

Do you know that you can get someone’s attention in an email message or a meeting invite with the @ symbol, followed by their name? Not only their name gets highlighted in the message body or invite details, but Outlook will automatically add them to the To line of the email or meeting invite, and they’ll see the @ symbol next to the message in their Inbox.

1. In the body the email message or calendar invite, enter the @ symbol and the first few letters of the contact’s first or last name.

Add the @ symbol and the first few characters of a person's name

2. When Outlook offers you one or more suggestions, choose the contact you want to mention. By default, the contact’s full name is included and added to the To: line.

The mentioned person's full name and email are shown by default

3. You can delete a portion of the mention, for example, everything other than the person’s first name.

You can choose to show only a person's first name

Source: Use @mentions to get someone’s attention