Rated 2 out of 5 stars
I have two issues with this extension:
1. The icon displayed is counterintuitive. I would expect the smaller one to indicate that I was the sole receipient, and the larger one to indicate that there were multiple recipients. Obviously.
2. It only supports the default email address for the account. If you receive email at more than one email address (e.g. with a catch-all; domain owners will know what I mean), those email addresses are all ignored.
Edit: I appreciate that the extension supports identities. But why depend on identities at all? If an email has a *single* recipient, why not show a single-recipient icon? Why must the recipient be known to Thunderbird? Couldn't this at least be an option? I use an utter slew of identities, and I receive mail at all of them. Only one of them is an identity known to Thunderbird.
Thanks for your comment.To 1. The icon follows the rule of the same functionality provided by Google Mail. The aim of the plugin is to bring GMail's feature back to the desktop, and thus to not confuse users, I decided to use the same icon scheme. Anyways, there is already a feature ticket in the project's bugtracker to make this more flexible.To 2. The plugin supports multiple emails addresses as it takes all addresses into account that are registered as account identities (see Account Settings / Manage Identities). However, the plugin requires Thunderbird to be restarted after identities have been added/removed.
Edit: The addon is now configurable and adds a different visualization, that is not following the google style (which you consider counter intuitive). The new style shows one arrow if the mail is sent only to one of your identities, two arrows if one of your identities is included in the recipients list and three arrows if the mail was sent to a mailing list. The idea of the addon relies on the connection to identities because it aims at visualizing that a mail was sent directly to you and not how many recipients were in the To-list.