My Subscriber gets asked to approve their messages because the system thinks it's spam
If you have turned on the feature to stop spam from going to your list.
http://help.mail-list.com/m/59124/l/558410
and a subscriber is consistently having to approve their messages, here are some tips to help them.
The self moderate messages that look like spam option will return emails that look like spam to the sender to approve
Subject: reply to release your mail (spammod14443441899711)
Therefore, make sure the messages from your subscriber do not look like spam.
Make sure they are only sending the email to your listserv, and not including a bunch of other addresses in the To: or Cc: lines
Sending to all of these addresses, looks spammy.
Put just one email address in the To: line, and none in the Cc: line.
Make sure the message has come content, and is not real real short or just contains a link
Messages that are very short or just contain a link are frequently spam.