diff --git a/mozilla/mail/app/profile/thunderbird.js b/mozilla/mail/app/profile/thunderbird.js
index 2740116b6bd..bc59208da45 100644
--- a/mozilla/mail/app/profile/thunderbird.js
+++ b/mozilla/mail/app/profile/thunderbird.js
@@ -50,6 +50,7 @@ pref("mailnews.attachments.display.largeView", false);
 pref("mail.pane_config.dynamic",            0);
 pref("mailnews.display.sanitizeJunkMail", true);
 pref("mail.standalone", true); 
+pref("editor.singleLine.pasteNewlines", 4);  // substitute commas for new lines in single line text boxes
 
 /////////////////////////////////////////////////////////////////
 // End seamonkey suite mailnews.js pref overrides