Signup Status Mailer not accepting email tokens

Hello,

I see the issue queue here is pretty old, but I noticed the dev versions were updated recently, so here goes in case someone is watching this queue:

I'm trying to set up the signup status mailer to send messages to node authors. I can't seem to get the email field to accept any of the email tokens available. I get the error

[author-mail] is not a valid e-mail address.

Any ideas on a fix or workaround ?

Thanks !