Hi Fabian,

Thanks for following this up. I had already looked at the lightning FAQ you link to - and thought that the last item might be the right one to post to:

Which newsgroup or forum discusses Sunbird and Lightning?

Two Sunbird-/Lightning-related newsgroups exist on the news.mozilla.org news server. mozilla.support.calendar: This newsgroup is dedicated to users of Sunbird or Lightning. All user-related discussions (questions regarding the use of the product, tips and tricks, workarounds or enhancement requests) should be posted here. mozilla.dev.apps.calendar: This newsgroup is dedicated to the current and future developers of Sunbird or Lightning. All developer-related discussions (how to best fix a particular bug, how to use a particular interface to extend the product or all discussions regarding future product planning) should be posted here. If you still need help, feel free to post a question in the MozillaZine Calendar Forum.

Unfortunately the link given at news.mozilla.org in the FAQ doesn't work :(

Right, the information there seems outdated so I am hoping to get something current here.

Did you try the forum?

http://forums.mozillazine.org/viewforum.php?f=46

news.mozilla.org is a newsgroup server but has unhelpfully been shown as an URL. That's a "feature" of this website.

In Thunderbird, File|New|Other Accounts|Newsgroup

http://ilias.ca/moznewsgroups-tb

(I know this is an old topic - I am posting this for new people coming along)

The direct line to developers is bugzilla. The link to bugzilla is right on the project page at https://www.thunderbird.net/en-US/calendar/