Email notifications currently are sent to all recipients using the To: email header line. Each mail is stored in user mailboxes. The names of all other recipients are copied in each message. On large WebNotify lists (such as Codev) extra scrolling can be required to even see the content of the notification email. This is true because the To: line is customarily displayed at the top of messages. This can be interpreted by some as a privacy issue. While a general feeling of comradery with other notification recipients is possible, a lack of a feeling of sophistication is also possible. Email notification is a primary "touch-point" between the TWiki system and the user. Extra care is not unwisely spent on highly used touch-points. As these messages are sent both frequently and potentially to many users storage resources can reliably be expected to be consumed.

I am proposing no functional changes but a small refinement. The change is to simply use the Bcc: email header instead of the To: header when sending notification email. The full recipient list is an unnecessary redundancy. The patch can be applied to templates/mailnotify.tmpl.

--- mailnotify.tmpl.orig        2001-11-30 22:51:37.000000000 -0800
+++ mailnotify.tmpl     2002-10-23 04:20:18.000000000 -0700
@@ -1,5 +1,6 @@
 From: %WIKIWEBMASTER%
-To: %EMAILTO%
+To: %WIKIWEBMASTER%
+Bcc: %EMAILTO%
 Subject: %WIKITOOLNAME%.%WEB% - Automated notification of topic changes
 MIME-Version: 1.0
 Content-Type: multipart/mixed; boundary="------------2D594AE113AD25493C2C7246"

I see no value in this repetitive storage of names in each user's mail store. The information regarding changes to a particular WebNotify list can be seen in the dated RCS diffs of the WebNotify topic itself. As TWiki use scales I see this very small but exponential storage burden on (corporate) email system requirements growing. While perhaps only an incremental improvement I am sure corporate email admins will appreciate the shortest notification messages possible.

-- GrantBow - 23 Oct 2002

This is similar to BccEmailsToWebNotifyList which I have now marked as BugDuplicate since Grant expressed his so much more eloquently. And proposed a solution....

-- RossC - 24 Oct 2002

The BCC is a simple solution to get rid of the big TO list. I have one little concern with the BCC list. Some spam filters reject e-mail where the recepient is not in TO, especially if FROM and TO are identical. Any experience in regards to this?

The real solution is to send out individual e-mails, this enables also individualized notifications, like CustomizableEmailNotification, DiffsInNotifyEmail, MailNotifyInPlainTextFormat. See also overview in EmailNotificationEnhancements.

-- PeterThoeny - 26 Oct 2002

Thanks for commenting Peter. I did put a TopicClassification of FeatureHack. While there may be better longer term solutions in consideration I am hoping this will help improve the situation short term for those that choose to apply this little patch.

-- GrantBow - 26 Oct 2002

This sounds useful, but IMO should be a configurable option. When a TWiki site is starting up, it's useful to know who else is on WebNotify and the storage cost is not an issue. For larger sites, BCC or customised emails are definitely a good idea.

-- RichardDonkin - 28 Oct 2002

IMHO, if seeing the subscriber list is desirable, it should be part of the message body, instead. That would allow anti-spam obfuscating, too.

-- RobertBagwill - 28 Oct 2002