Thunderbird is a free mail client, news reader and RSS client by the Mozilla Foundation. It is one of the most widely used email clients and is available for all major operating systems. The biggest drawback of Thunderbird is the limited cooperation with Exchange servers. Although mails on Exchange servers can be easily retrieved via IMAP (or POP3), due to the proprietary MAPI protocol the usual Exchange functionality is not available in Thunderbird (see point 3).

You can download Thunderbird from the Mozilla website. After installing and starting the program, you will be prompted to enter your name, email address and password.

Since Thunderbird does not propose any settings, or offers incorrect settings, the correct settings must be entered manually. To do this, click “edit manually” in the bottom left corner and enter the following data:

First line: Incoming mail server: IMAP Server Address: email.gwdg.de Port: 993 SSL: SSL / TLS Authentication: Normal password

Second Line: Outgoing mail server: smtp Server Address: email.gwdg.de Port: 25 or 587 SSL: STARTTLS Authentication: Normal password

Third Line: Username: GWDG\userid Since the Exchange server is in an Active Directory domain, the domain must be specified: GWDG\userid (users from other domains have to modify the domain accordingly).

Signatures can be created both in the program and imported as external files. In the first case, enter the desired signature text under Edit → Account Settings → Account → Signature Text. If the box “use HTML” is checked, you can also use common html commands in the signature. External files, text, HTML or image files can be imported in the same place with the button “Instead, attach a file as a signature”. These should be appropriately saved in the Thunderbird profile folder (/Users/username/Library/Thunderbird/Profiles/RandomProfilCode.default/).

As described above Thunderbird does not support Microsoft's MAPI protocol. For those who do not want to give up Thunderbird, it has some very basic options to access Exchange calendars, tasks and address book. The first choice (from Exchange 2007) is the calendar plugin Lightning in combination with the plugin Provider for Microsoft Exchange. Another alternative is DavMail, a POP / IMAP / SMTP / Caldav / CardDAV / LDAP gateway, which can communicate to the Exchange server. A simpler solution would be to “outsource” calendar and address book and to set up and use iCal and Address Book independently from Thunderbird.