diff --git a/SoObjects/Appointments/SOGoAppointmentFolder.m b/SoObjects/Appointments/SOGoAppointmentFolder.m
index 3eb4153fb..5c561ab72 100644
--- a/SoObjects/Appointments/SOGoAppointmentFolder.m
+++ b/SoObjects/Appointments/SOGoAppointmentFolder.m
@@ -2548,7 +2548,7 @@ firstInstanceCalendarDateRange: (NGCalendarDateRange *) fir
                                 XMLNS_GROUPDAV, nil];
           [colType addObject: gdVTodoCol];
         }
-      if ([nameInContainer isEqualToString: @"personal"])
+      if ([nameInContainer isEqualToString: @"personal"] || [nameInContainer isEqualToString: @"Personal"])
         [colType addObject: [NSArray arrayWithObjects: @"schedule-outbox",
                                      XMLNS_CALDAV, nil]];
     }
diff --git a/SoObjects/Appointments/SOGoUserFolder+Appointments.m b/SoObjects/Appointments/SOGoUserFolder+Appointments.m
index cc9dfd6dc..0060637e5 100644
--- a/SoObjects/Appointments/SOGoUserFolder+Appointments.m
+++ b/SoObjects/Appointments/SOGoUserFolder+Appointments.m
@@ -189,8 +189,8 @@
 }
 
 - (NSArray *) davCalendarScheduleOutboxURL
-{
-  return [self _davSpecialCalendarURLWithName: @"personal"];
+{  
+  return [[context request] isMacOSXVenturaCalendarApp] ? [self _davSpecialCalendarURLWithName: @"Personal"] : [self _davSpecialCalendarURLWithName: @"personal"];
 }
 
 - (NSArray *) _calendarProxiedUsersWithWriteAccess: (BOOL) write
diff --git a/SoObjects/Mailer/SOGoMailAccount.m b/SoObjects/Mailer/SOGoMailAccount.m
index 277c98650..b7273283c 100644
--- a/SoObjects/Mailer/SOGoMailAccount.m
+++ b/SoObjects/Mailer/SOGoMailAccount.m
@@ -136,6 +136,12 @@ static NSString *inboxFolderName = @"INBOX";
   namespaceDict = [client namespace];
 
   namespace = [namespaceDict objectForKey: @"personal"];
+  // FIXME: Improve MacOSX Ventura support 
+  // Check if the problem will be fixed by Apple or if this fix should be kept in the future
+  // Ticket #5639
+  if ([[context request] isMacOSXVenturaCalendarApp]) {
+    namespace = [namespaceDict objectForKey: @"Personal"];
+  }
   if (namespace)
     [self _appendNamespace: namespace toFolders: folders];
 
diff --git a/SoObjects/SOGo/SOGoFolder.m b/SoObjects/SOGo/SOGoFolder.m
index 0932150de..64958aadf 100644
--- a/SoObjects/SOGo/SOGoFolder.m
+++ b/SoObjects/SOGo/SOGoFolder.m
@@ -200,16 +200,16 @@
 
   selfName = [self realNameInContainer];
   otherName = [otherFolder realNameInContainer];
-  if ([selfName isEqualToString: @"personal"])
+  if ([selfName isEqualToString: @"personal"] || [selfName isEqualToString: @"Personal"])
     {
-      if ([otherName isEqualToString: @"personal"])
+      if ([otherName isEqualToString: @"personal"] || [otherName isEqualToString: @"Personal"])
 	comparison = NSOrderedSame;
       else
 	comparison = NSOrderedAscending;
     }
   else
     {
-      if ([otherName isEqualToString: @"personal"])
+      if ([otherName isEqualToString: @"personal"] || [otherName isEqualToString: @"Personal"])
 	comparison = NSOrderedDescending;
       else
 	comparison = NSOrderedSame;
diff --git a/SoObjects/SOGo/SOGoGCSFolder.m b/SoObjects/SOGo/SOGoGCSFolder.m
index efdd33860..cad9ac1b5 100644
--- a/SoObjects/SOGo/SOGoGCSFolder.m
+++ b/SoObjects/SOGo/SOGoGCSFolder.m
@@ -150,7 +150,7 @@ static NSArray *childRecordFields = nil;
   if ([pathElements count] > 1)
     ocsName = [pathElements objectAtIndex: 1];
   else
-    ocsName = @"personal";
+    ocsName = [[context request] isMacOSXVenturaCalendarApp] ? @"Personal" : @"personal";
 
   path = [NSString stringWithFormat: @"/Users/%@/%@/%@",
 		   login, [pathElements objectAtIndex: 0], ocsName];
diff --git a/SoObjects/SOGo/SOGoParentFolder.m b/SoObjects/SOGo/SOGoParentFolder.m
index a378ff027..61dade520 100644
--- a/SoObjects/SOGo/SOGoParentFolder.m
+++ b/SoObjects/SOGo/SOGoParentFolder.m
@@ -173,7 +173,7 @@ static SoSecurityManager *sm = nil;
   {
     if (folderType == SOGoPersonalFolder)
     {
-      folderName = @"personal";
+      folderName = [[context request] isMacOSXVenturaCalendarApp] ? @"Personal" : @"personal";
       folder = [subFolderClass objectWithName: folderName inContainer: self];
       [folder setDisplayName: [self defaultFolderName]];
       [folder setOCSPath: [NSString stringWithFormat: @"%@/%@", OCSPath, folderName]];
@@ -241,7 +241,7 @@ static SoSecurityManager *sm = nil;
     }
     if (folderType == SOGoPersonalFolder)
     {
-      if (![subFolders objectForKey: @"personal"])
+      if (![subFolders objectForKey: @"personal"] || ![subFolders objectForKey: @"Personal"])
         [self createSpecialFolder: SOGoPersonalFolder];
     }
     else if (folderType == SOGoCollectedFolder)
diff --git a/SoObjects/SOGo/SOGoUser.m b/SoObjects/SOGo/SOGoUser.m
index 1255ec231..ed9f78303 100644
--- a/SoObjects/SOGo/SOGoUser.m
+++ b/SoObjects/SOGo/SOGoUser.m
@@ -1059,7 +1059,7 @@
 
 - (SOGoAppointmentFolder *) personalCalendarFolderInContext: (WOContext *) context
 {
-  return [[self calendarsFolderInContext: context] lookupPersonalFolder: @"personal"
+  return [[self calendarsFolderInContext: context] lookupPersonalFolder: [[context request] isMacOSXVenturaCalendarApp] ? @"Personal" : @"personal"
                                                          ignoringRights: YES];
 }