Go to
http://www.scalix.com/community/downloads/index.php, then on the left click on Community Edition, then fill in your details. The next page has a link right at the bottom, above the footer:
For older Scalix Community Edition downloads please visit our archive. Click on the word "archive" and scroll down until you find the
Binary Client Packages. The 11.1.0 connector is there.
If possible I would suggest an upgrade (server and clients) to 11.4.0, though. Lots of feature improvements and bugfixes.