In the message editing window in Outlook, you can add reflection for the selected text in the message body as follows:

1. In the message body, select the text you will add reflection for.

2. Go to the Font group on the Format Text tab, and click and anchor  at the bottom-right corner to open the Font dialog.
Tips: You can also press Ctrl + D keys to open the Font dialog.

3. In the Font dialog, click the Text Effects button at the bottom-left corner.

4. In the Format Text Effects dialog, enable the Text Effects tab, and click the arrow  before Reflection to expand this section.

5. Please configure the reflection parameters as you need.

• Presets: Select one style of reflections from the Presets drop-down list as you need.
  
  Tips: If the chosen preset reflection meets your needs, you can finish the configuring, otherwise, please go ahead to set other parameters.
• Transparency: Drag the slider or enter a percentage to set the transparency of your reflection.
• Size: Drag the slider or enter a percentage to set the reflection size.
• Blur: Drag the slider or enter a number of points to set how long the reflection becomes blurry.
• Distance: Drag the slider or enter a number of points to set how long the reflection is from the selected text.

6. Click the OK buttons to save the settings and close both dialogs.

So far, the reflection has been added for the selected text in the message body.

If you need to remove the reflection from text in the message body, you can do as follows:

1. In the message body, select the text whose reflection you will remove.

2. Press Ctrl + D keys to open the Font dialog, and then click Text Effects button in the Font dialog box.

3. In the Format Text Effects tab, enable the Text Effects tab, select None from the Presets drop-down list in the Reflection section, and click the OK buttons to close both dialogs.