The frontend section on the download page ( https://www.sogo.nu/download.html#/frontends ) is because of various reasons outdated:

1) The list of Thunderbird versions is only going to 91. The newest version is now 115. I recommend to add the versions 102 and 115. Plus I would remove all versions which you don't want to support anymore. Or at least all versions where the Integrator and the Connector where two different plugins or where the calendar was still an external plugin (Lightning).

2) It would be great if there where at least one or two sentences why I should download the Connector. Because it is not clear if it is still needed or not.

3) I would remove the BlackBerry section now as I don't think someone is still using this combination. The last few BB devices where Android devices anyway.

4) According to the website of the Outlook synchronizer the official support versions are: Office 365, 2019, 2016, 2013, 2010 and 2007.
You should adjust this list as well. Furthermore Outlook is probably still the most used client worldwide. Hence I would put it at the top of the page as it is what most users will search for.