There is no option in Outlook to permanently change the zoom level in the reading pane.
For a permanent change, I see two solutions.
Solution 1 : VBA macro
Use the VBA macro below, detailed in the article
How to Always Open Your Email in a Custom Zoom Level with Outlook VBA.
Private WithEvents objInspectors As Outlook.Inspectors
Private WithEvents objMail As Outlook.MailItem
Private Sub Application_Startup()
Set objInspectors = Outlook.Application.Inspectors
Private Sub objInspectors_NewInspector(ByVal Inspector As Inspector)
If TypeOf Inspector.CurrentItem Is MailItem Then
Set objMail = Inspector.CurrentItem
Private Sub objMail_Open(Cancel As Boolean)
Dim objMailDocument As Word.Document
'When opening an email which is not a new mail
If Len(Trim(objMail.Subject)) <> 0 Then
Set objMailDocument = objMail.GetInspector.WordEditor
'Change "150" as per your desired zoom level
objMailDocument.Windows(1).Panes(1).View.Zoom.Percentage = 150
- Start Outlook
- Press Alt+F11
- Access the
ThisOutlookSession project on the left side and double-click
- Copy the above VBA code into this project window
- Digitally sign this code by the “Tools” button in the toolbar and
choosing “Digital Signature…” from the drop-down list.
- In the popup dialog box, enable a digital certificate
- Exit the “Microsoft Visual Basic for Applications” window and restart Outlook
to activate the new VBA project
- From now on, every time when you open an email which is not a fresh new mail, the email will display in your custom zoom level
Solution 2 : Zoom Email Windows (trialware, $9.95)
Another option is to get the trialware
Zoom Email Windows ($9.95) :
The Zoom Email Windows tool for Outlook automatically zooms all Outlook reading pane windows. It zooms every Outlook window to your specified zoom factor. It’s perfect for being able to instantly and clearly see the email and other Outlook windows.