Thunderbird

By my reading of the exhaustively named Bug 558931 - Composition's recipient autocomplete does not / fails to show all matching address book entries (implement partial/substring matching for each of multiple search words; find 2nd words etc.

Pretty easy, once you know where to look-- not under Calendar, but under File > New > Calendar

then On the Network and (probably) iCal/ICS.

http://blog.vinay-srini.com/2010/02/thunderbird-3-hack-fix-number-of.html

I have a lot of e-mail accounts. Some of them check with a different domain name than to which is registered with a security certificate for the same IP address. To check mail, you have to click OK before it times out. Every. Time.

There's a bug report that may never be resolved:
https://bugzilla.mozilla.org/show_bug.cgi?id=221552

Desktop applications of broad or critical utility.

All Platforms: