On Thu, Jun 03 2021, Eric Abrahamsen wrote:

> in mid-2019 I made some fairly large changes to Gnus to use decoded
> group names everywhere, and in the process fixed several bugs related
> to non-ascii group name.

Hello Eric,

Now I use Emacs from git-master. Still the same problem.

Here some details for the group "céline":

- There is this line in ~/Mail/active: "céline 153 1 y"
- Then I reply to a message in this group with "Gcc: céline"
- This appears in the *Messages*:
  Sending...
  Sending via mail...
  Wrote /home/peter/Mail/c\303\251line/154  (2 non-printable characters)
  Sending...done
- When entering the group "céline", the new message is hidden.
- There are now 2 lines in the active file:
  céline 154 1 y
  céline 153 1 y

I guess, that this should be reproducible with any nnml group with
accented characters in the group name.

TIA for any help,
-- 
           Peter