I believe this has been fixed in debian's 3.0.dfsg.1-5¹. We're now at 3.0.dfsg.1-7 and 3.0.dfsg.1-8 is making its way thru.
¹ Look for the patch 03-proper_cmd_handling.diff: http://packages.debian.org/changelogs/pool/main/m/mail-notification/mail-notification_3.0.dfsg.1-7/changelog.html#versionversion3.0.dfsg.1-5 -- No longer launches mail reader after upgrading to etch https://launchpad.net/bugs/67492 -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs
