Overview: It would be nice to have the option to not send an email to users on the notification list (owner, reporter, CC list) when updating a ticket with insignificant changes.
Use case: we work with several external vendors who do not have logins for our trac instance, but are often added to a ticket's CC list. Typically an email discussion will go on outside of Trac, and I will end up pasting each email into the Trac comment history for the relevant ticket.
When I add the emails to the comment history, the owner, reporter, and CC list all receive notifications of the changes to the tickets ... but they typically have already seen the email so it is just a nuisance to them to receive a notification when I paste the email into the ticket history. Particularly for the vendors, they are on the CC list and therefore get notified when I paste their own email into the ticket change history.
Furthermore, what sometimes happens is that there are so many emails pasted into the ticket history and resulting notifications that users get in the habit of deleting a bunch of ticket notifications and miss important notifications. Imagine I paste 10 emails into the change history, and then write a summary. The typically user looks at the first 2 or 3 notifications and then seeing that the information is redundant, deletes the rest of them.
Enhancement: A checkbox Don't send change notification that is unselected by default and appears next to the Submit Change button.
This feature would work nicely in conjunction with Ticket #4269. That way you get a nice summary of if and to whom emails where sent.
