diff --git a/ChangeLog b/ChangeLog
index db9aa8026..3cff3127e 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,9 @@
+2008-09-22  Wolfgang Sourdeau  <wsourdeau@inverse.ca>
+
+	* SoObjects/SOGo/NSString+Utilities.m ([NSString
+	-asQPSubjectString:encoding]): replace spaces with underscore
+	characters to comply with rfc 2047.
+
 2008-09-17  Wolfgang Sourdeau  <wsourdeau@inverse.ca>
 
 	* UI/MailPartViewers/UIxMailPartViewer.m ([UIxMailPartViewer
diff --git a/SoObjects/SOGo/NSString+Utilities.m b/SoObjects/SOGo/NSString+Utilities.m
index c3996e07f..6adbe9e6f 100644
--- a/SoObjects/SOGo/NSString+Utilities.m
+++ b/SoObjects/SOGo/NSString+Utilities.m
@@ -331,8 +331,11 @@ static NSMutableCharacterSet *urlStartChars = nil;
 			       encoding: NSASCIIStringEncoding];
   [qpString autorelease];
   if ([qpString length] > [self length])
-    subjectString = [NSString stringWithFormat: @"=?%@?Q?%@?=",
-			      encoding, qpString];
+    {
+      qpString = [qpString stringByReplacingString: @" " withString: @"_"];
+      subjectString = [NSString stringWithFormat: @"=?%@?Q?%@?=",
+				encoding, qpString];
+    }
   else
     subjectString = self;