diff --git a/source/appModules/hxmail.py b/source/appModules/hxmail.py
index e08e44bb3a6..4036550dbd8 100644
--- a/source/appModules/hxmail.py
+++ b/source/appModules/hxmail.py
@@ -12,13 +12,32 @@
 
 class MailWordDocumentTreeInterceptor(WordDocument.treeInterceptorClass):
 
-	def _get_isAlive(self):
-		return super(MailWordDocumentTreeInterceptor,self).isAlive and self.rootNVDAObject.shouldCreateTreeInterceptor
+	_wasInReadingPane: bool = False
+
+	def event_treeInterceptor_gainFocus(self):
+		isInReadingPane = self.rootNVDAObject.isInReadingPane
+		if isInReadingPane != self._wasInReadingPane:
+			self._wasInReadingPane = isInReadingPane
+			# The base WordDocument TreeInterceptorClass forces focus mode by default
+			# As a TreeInterceptor is created for all word documents
+			# so that the NVDA elements list is available.
+			# However, Windows 10 Mail's reading pane should use browse mode.
+			if isInReadingPane:
+				self.disableAutoPassThrough = False
+				self.passThrough = False
+			else:
+				self.disableAutoPassThrough = True
+				self.passThrough = True
+		super().event_treeInterceptor_gainFocus()
 
 class MailWordDocument(WordDocument):
 
 	treeInterceptorClass=MailWordDocumentTreeInterceptor
-	def _get_shouldCreateTreeInterceptor(self):
+
+	# typing information for isInReadingPane property
+	isInReadingPane: bool
+
+	def _get_isInReadingPane(self) -> bool:
 		# Locate the Reading pane in the ancestors
 		condition=UIAHandler.handler.clientObject.createPropertyCondition(UIAHandler.UIA_ClassNamePropertyId,"ReadingPaneModern")
 		walker=UIAHandler.handler.clientObject.createTreeWalker(condition)