Activity plugin and Posting

Is their a way to update the automatic subject line that gets created by wall post notifications?

Right now is says "Community at Discovery - New group post"

I would like the emails subject o include the group that's being posted in.

Ex. "Community at Discovery - Prayer group post"

It's a language string so yes you can modify it to whatever you like using language overrides functionality explained in my previous reply. You can use the language finder explained below to find language strings.

www.joomlapolis.com/blog/kyle/18712-language-key-and-text-finder

You can use [group_name] in your language override to substitute in the groups name.

I have tried using the search tool for a long time, but I cannot figure out where the subject is coming from..

It searches the key and the string. So for example just searching for "new group post" finds the below.

Key: NEW_GROUP_POST_098c50
Text: New group post

Your sites name is prefixed by CBs notification functionality it self and not by CB. If you want that removed you have to translate the below string.

Key: EMAIL_NOTE_SITENAME_SUBJECT
FROM: [sitename] - [subject]
TO: [subject]