More Anti Spam improvements

   More Anti Spam improvements Ø In the Mail Archive user filters, the domain names are forced to lowercase.  Ø When the option to send quarantine reports is enabled but there is no spam to report about, the report is sent with an empty list. It’s now possible to avoid sending such reports by unchecking this option, that is enabled by default. This option is available in menu Anti Spam > Daily Reports.  Ø  When the RBL sensitivity level changes, it doesn't affect any more the score of the Administrative Notices.