Since we have changed
$wgPasswordSender = "Genwiki(a)genealogy.net".net";
$wgPasswordSender = "GenWiki Nachrichten <KeinEmpfang(a)genealogy.net>"t>";
That's not a valid e-mail address. $wgPasswordSender takes a string that
must be a valid e-mail address representing the account to send mail from,
not some random string that you'd like to appear in the 'from' field. Hence
all attempts to send mail headered as being from that account fail, so you
get no messages.
--HM