I'm working on integrating Dave's feature for comment notification via
email into Manila:

http://scriptingnews.userland.com/2003/08/25#When:6:55:47AM

There are a few aspects of the feature that are worth discussing with
developers on the list before we release the feature.

*** Preference for enabling notification

A new preference for whether the feature is enabled: "Do you want
notification sent when a new comment is posted?"

The value will default to the same value as the "Do you want
notification sent when a new discussion group message is posted?" pref
on the Editorial prefs page. This way sites which send notifications
when new DG messages are posted, will default to also sending
notification for new comments.

I think the pref belongs on the Radio Hosting prefs page, since that's
where the other comment-related prefs reside. Two other options are the
Editorial prefs page, where the new message/story/picture notification
prefs are located, or the News Items prefs page, where the news item
email notification pref is located.

*** Notification recipients

Consider a news item site that has multiple authors. In this case, the
default notification list may include all authors, or only some (or
none). When a new author is added to the site (given permission to post
news items), their email address would have to be manually added to the
notification list in order to receive comments via email.

Another issue is that all authors on the site would see comments in
response to all news items, not just the items they wrote themselves.

I think it would be useful to have a preference for who gets notified
-- "Send notification to:", with three options: "notification list and
news item author", "notification list only" and "news item author only".

The default is the first option. (If the author of the news item is
also in the notification list, he will receive only one email.)

*** Subscriptions via email

Manila's discussion group has an optional feature for subscribing to
discussion group threads via email. A similar feature for comments
would make it easy for people who post comments, to follow subsequent
conversation without having to reload the comment page.

A checkbox would be added to the comment post form in comment pop-up
windows: "Check this box to receive future comments via email." The
default is unchecked.

This feature would respect the server level Manila preference for
whether email subscriptions to discussion threads are allowed. (See the
Settings -> Manila -> Preferences page in the Frontier Admin site.) If
email subscriptions are not allowed on the server, then the checkbox
would not appear in the comment post form.

*** Callbacks

When a comment is posted, Manila will call new callback scripts in
config.manila.callbacks.commentPost.

The callbacks take a single parameter, pta (the address of the page
table).

When callbacks are called, the page table will contain a sub-table
called manilaCommentInfo, which in turn contains information about the
newly created comment. Sub-items of manilaCommentInfo are:

siteName -- the name of the site

inResponseToPostNum -- the message number of the news item that the
comment is in response to

inResponseToUrl -- the permalink URL of the news item

inResponseToTitle -- the title of the news item

commenterEmail -- the email address of the person who posted the comment

commenterName -- the name of the person who posted the comment

commenterUrl -- the web site url of the person who posted the comment

commenterIpAddress -- the IP address that the comment was posted from

commentText -- the text of the comment

*** Feedback

Please post any questions or comments to the list as a reply to this
message.

Thanks,
-Jake