Mails are sorted chronologically in Thunderbird by default but they are not grouped. Grouped means special folders for mails that arrived today, yesterday, last week, two weeks ago and old mail. This way of sorting mails is incredibly helpful for a better overview in my opinion.
Thunderbird Duplicate Contact Manager
I introduced a Thunderbird extension to remove duplicate mails yesterday and I want to continue today by writing about a Thunderbird extension that checks for duplicates in the Thunderbird address book. The add-on handles one address book at the time currently which is a little unfortunate but the author promises to deliver the possibility to check all existing address books in a future version.
Thunderbird Remove Duplicate Mails
Duplicate mails can be a problem in the most advanced email applications. It does not matter if you use Outlook, Thunderbird or a self coded mail program, duplicate mails can be a problem in all of them. This can happen for instance if you merge folders in the mail program or if a server or download error has the result that the mails are downloaded twice from the mail server.
Use Thunderbird and Thunderbird Portable
Thunderbird portable is the portable version of Thunderbird, it does not require an installation which makes it an ideal tool for USB sticks and removable storage devices. I’m using Thunderbird on my desktop computer and decided that I wanted to use Thunderbird Portable on my USB drive to be able to check mails when on the road.
Remove Duplicate Address Book Entries in Thunderbird
It can happen that you end up with duplicate address book entries in Mozilla Thunderbird and wonder how you can remove them so that only one entry per contact is visible in the Thunderbird Address Book. The current Thunderbird address book is most likely fragmented or corrupted and the easiest way to fix that is to create a new Address Book and copy the contents of the old Address Book into the new one.
How to get mail from all thunderbird accounts at once
The email client Thunderbird does not necessarily retrieve messages from all of your mail accounts at startup. By default the first mail account will be checked on startup and all mail accounts will be checked every ten minutes. The following user.js tweak changes this behavior in the way that Thunderbird retrieves mail from all accounts at startup as well.

