From Tom Wolff's post on the Confluence forum:

One of the most powerful aspects of Confluence is its email notification of new and changed content. I'm sure this matter has been discussed previously, but I didn't find readily a forum posting that summarizes the issues as my wiki users and I see them.

The problem is that users receive too many email notifications that most people consider unhelpful at best and very annoying at worst. The control mechanisms currently available in Confluence 2.10 are inadequate to control sending email notifications, and "watch" options available to users can not make up for this deficiency.

I think we can divide actions and content into new, edited and removed pages, comments, news, and attachments as summarized below:

Content Type New Edited Removed
Page - X -
Comment - - -
News - - -
Attachment - - -

The X shows the only option, as far as I can tell, for preventing sending email notifications.

Per this chart, email notifications are automatically sent out for all combinations EXCEPT for edited pages based on whether users check the "Minor Change?" option box. (Searching the Confluence forum for "minor change" provides several conversations on this matter back at least to 2006.)

We find particularly annoying email notifications resulting from removing content. As administrator, I have removed pages, comments, and attachments as inappropriate or obsolete and have almost certainly not wanted to bring attention to that removed content.

We also believe email notifications about attachments (added, moved, or removed) to be of very low value. Attachments are almost always supporting or described by the page content itself which will be the subject of its own email notification.

My users and I believe it is past time for Atlassian to provide users and administrators better control in Confluence over sending these email notifications. This includes, but is not limited to, improving the "Minor Change?" option with clear option buttons or similar mechanisms as discussed in other forum entries.

I look forward to elaboration of this issue by other users and action by Atlassian on this matter.