When your Outlook 2007 mail message text is larger or small than usual…

It sometimes happened to me that when I am composing a new mail, suddenly the while message font is became large and I don't know what I had pressed any key to let it happen. today it happened again and I decide to find the cause of it!

after a search of hotkeys in Outlook 2007 help file, found the answer...

Outlook Home > E-mail > Fonts and formatting

The text of my messages is larger or smaller than usual

When you compose, reply to, or forward an e-mail message, and the message body (including the text) appears larger or smaller than the size that you typically see, you might have accidentally changed the zoom view setting.

When the zoom view is changed, the setting is persistent on all future messages you compose, reply to, or forward.

Note   The zoom view setting doesn't affect how recipients will see the message. Messages are always opened at 100-percent zoom view size.

You can adjust the zoom view in Microsoft Office Outlook 2007 in two ways — by using your mouse wheel button, or from within Outlook itself.

Use a mouse wheel button to change the zoom

If you have a pointing device, such as the Microsoft IntelliMouse pointing device, that has a wheel button, you can use the wheel button to zoom in on, or out of, the body of a message.

1. Click the message body.
2. Press or hold CTRL while you rotate the wheel button to zoom in or out.

Use the Ribbon controls to change the zoom

The zoom level of the message view can be changed in the Ribbon, which is part of the Microsoft Office Fluent user interface.

1. Click the message body.
2. On the Format tab, in the Zoom group, click Zoom.
3. In the Zoom dialog box, under Zoom to, click 100% for the default size, or use the other options to specify a custom zoom size.

   

Note   When the zoom view is changed, the setting is persistent on all future messages you compose, reply to, or forward.

So the reason why it was happened on me is that when I type fast and using my mouse around my messages, suddenly I moved the mouse scroll wheel while I was pressing the Ctrl key trying to copy (Ctrl-C) or paste (Ctrl-V) some paragraph.

Case closed! FYI.