Hallo, I have newly installed Thunderbird with Maildir (version 45.6.0). Thunderbird correctly saves all incoming and outgoing messages in a single file on disk. Every file gets a unique number, but there is no.eml suffix added. As a result, the files are not recognized by windows10 as being emails, and when I doubleclick on a file, Thunderbird isn't opened automatically. When I add the .eml suffix manually (which is tedious, time-consuming and prone to errors), the files get the Thunderbird icon, and by doubleclicking them Thunderbird is opened. But Thunderbird then shows each such file two times: one (with suffix) that can be found and one (without suffix) that cannot be foud by Thunderbird. After I let Thunderbird repair the folder, the doubles are gone and only the .eml files remain. As I am a new Thunderbird user, I am wondering wether I am overlooking something that should be obvious, or is this some bug in Maildir? Thanks for your answer.