Comment 2 for bug 957922

Thunderbird actually does turn the icon blue already, but not for all messages. The reason for this is people complained to me in Oneiric that the icon was being turned blue far too much. In fact, for some people (including me), the icon was blue pretty much permanently as long as Thunderbird was open, and this reduces the usefulness of the messaging indicator for notification of real-time messages to pretty much zero. In fact, people just got so fed up of it that they were asking me how to disable this feature in Thunderbird entirely.

I did consider making Thunderbird never turn the icon blue, but made a compromise which turns the icon blue in the following circumstances:

- The message is sent with high-priority OR
- The message is flagged (by a filter) OR
- The message is addressed directly to the recipient (eg, not CC) AND the message is not low prioirty AND the message wasn't automated AND the message is not from a mailing list

Some real life examples of how this works:
- If your boss sends you a message, it will turn blue
- It will not turn blue for normal mailing list traffic
- If someone replies to a message you sent to a mailing list, it will turn blue
- If Amazon sends you a marketing message which isn't marked as spam, it will not turn blue
- It will not turn blue for bug mail traffic (unless you have set up filters to flag messages you are particularly interested in, eg, bugs with high importance or bugs you are assigned to)
- If Facebook emails you with a friend request, it will not turn blue.

It has been like this for pretty much the whole 12.04 cycle, and so far people have been much quieter about it (ok, it could be that they got so sick of the icon turning blue in Oneiric that they just disabled the feature entirely and are no longer using it). I think the current implementation works quite well though, and I'd prefer suggestions to improve it rather than just turning the icon blue for all messages.

Remember, we also show a count on the launcher, which is displayed all the time by default in Precise.

And, if you want the icon to turn blue for all messages, we have an about:config pref for that. But you'll soon realise how annoying that is if you get more than a dozen or so mails per hour.

The current implementation is more like Gwibber, which keeps counts of messages in the messaging menu without turning it blue. IMO we should only really turn the icon blue if we think that the message is important enough to interrupt your current workflow. Most e-mail does not fall in to this category.