leakage when Firefox does DNS prefetching for URLs contained in emails.
- Added the ability to configure Google Mail (Gmail) as the mail server
behind SquirrelMail.
- - Explicitly disable caching for left_main and right_main pages (#2983134).
- Fix error with SpamCop reporting plugin not being able to send report as
emails (#1795310).
- Fix typo in SpamCop plugin.