'error.no_groups' => 'Your database is empty. Login as admin and create a new group.',
'error.upload' => 'File upload error.',
'error.range_locked' => 'Date range is locked.',
-'error.mail_send' => 'Error sending mail.',
+'error.mail_send' => 'Error sending mail. Use MAIL_SMTP_DEBUG for diagnostics.',
'error.no_email' => 'No email associated with this login.',
'error.uncompleted_exists' => 'Uncompleted entry already exists. Close or delete it.',
'error.goto_uncompleted' => 'Go to uncompleted entry.',