Facebook just posted to its official Page that is testing new summary emails for users “who are very active on Facebook and receive lots of email notifications”. Rather than sending individual emails, the notifications will be compiled into occasional digests. Those in the test will have their account settings automatically changed to turn off most of their email notifications, which might surprise and annoy some users, though they’ll be able turn them all back on by unchecking the new “Email Frequency” account setting.

Summary emails could help reduce inbox clutter for Facebook power users — ones the site wants to keep happy because their actions drive reengagement for less active users. However, forcibly changing account settings could upset some users even if it they eventually find the summaries valuable.

Facebook defaults to sending users individual email notifications for over 70 different actions on the site. If users are admins of Pages, join noisy Groups, are frequently invited to Events, or play games, these notifications can quickly overrun their inboxes and lead them to ignore rather than read the alerts.

While users will still see red counters on the site’s top navigation bar when they return, getting them to actually click through email notifications is important to the site maintaining its high daily active user count. Often the actions users take in response to notifications, such as replying to posts on their wall, generate notifications for other users and create a loop that helps Facebook attain its massive engagement rates.

Solving the problem of excessive email notification frequency therefore seems somewhat obvious, but Facebook’s solution may be too aggressive. Though the end result of a cleaner inbox may benefit users, some may object on principle to having their account settings changed without their permissions.

Facebook should certainly look to address the issue, but its opt out test may do more harm than good. It should consider emailing those receiving too many email notifications with the choice to opt in to email summaries, or using a sidebar prompt to promote the feature. The perception that Facebook can change a user’s privacy or account settings at will already pushes potential users away from the service, and this change won’t help.

Update 9/20/2011: To inform users who’ve had their notifications settings changed, Facebook is sending the email below. By explicitly alerting users to the change, Facebook may be able to reduce the risk of backlash.