Mailbox in Thunderbird

When you create a ULYSSIS account, you get an email address: It is possible to check this mailbox via However, it is far more convenient and efficient to use a standalone email client. This article will explain the process of adding a mailbox to the Thunderbird client. Do note: this article is written for users who opted for a ULYSSIS mailbox. not for users who opted for a forwarded email address (more information about forwarders is available at


Thunderbird is a free and open-source email client made by Mozilla. It is available for download at The installation process is fairly easy and thus will not be covered in this article.

Adding a ULYSSIS mailbox to Thunderbird

If this is the first mailbox being added to Thunderbird, the following pop-up should come up:

First Open TB.png

If the pop-up did not come up, or this is not your first mailbox; it is possible to click the Email button (highlighted in blue in the screenshot below) under the "Set Up Another Account" section:

New Mailbox.png

Once the pop-up is present, it becomes possible to dial in the settings for a mailbox. The first step is to fill in the Email adress field:

Fill in email.png

Notice, the button "Configure manually..." on the bottom left has become clickable (as seen on the above screenshot). When this button is clicked, the pop-up should look like this:

Click Configure Manually.png

Now, fill in the information as follows:

Fill advanced.png
Manual settings
Protocol: IMAP SMTP
Port: 993 443
Authentication: Autodetect Autodetect
Username: ULYSSIS-username r-number


The ports used to configure a ULYSSIS mailbox, are not automatically recognized by Thunderbird. This means they should be entered manually instead of using the drop-down.

The "Re-test" button on the bottom right of the following screenshot is used to validate the settings. When pressed, the pop-up should look like this:

After Clicking Retest GOOD.png

If this test succeeds, the pop-up can be closed by pressing the "Done" button on the bottom right of the previous screenshot. When the pop-up closes, a mailbox should be added to the left side of the main Thunderbird window. By clicking on the inbox tab, the emails should load in (as seen in the last screenshot). After this first setup, the mailbox should synchronize automatically.

After Clicking GetMessages.png


When sending the first email after configuration, Thunderbird might show a pop-up: "Enter your password for r0000000 on". It is really important to enter your KU Leuven password (the password used for central login), otherwise your email will not be sent.