Hi,
We just upgraded to 2.4.5 and I can confirm that the errors are gone.
Before removing my temporary workaround 'mailbox_list_normalize_names_to_nfc=no', I checked for and found some non-NFC folders that were created since our cleanup and implementation of the workaround in May:
doveadm -o mailbox_list_normalize_names_to_nfc=no mailbox list -A | python3 -c 'import sys,unicodedata;[print(repr(l.rstrip())) for l in sys.stdin if l.rstrip()!=unicodedata.normalize("NFC",l.rstrip())]'
I renamed these with:
doveadm -o mailbox_list_normalize_names_to_nfc=no mailbox rename -s -u user@example.com 'old' 'new'
And then removed the workaround. I tested successfully that normalisation works now at folder creation time:
doveadm mailbox create -u test@example.com "$(python3 -c "import unicodedata,sys; sys.stdout.write(unicodedata.normalize('NFD','Anträge-nfdtest'))")"
On disk that ends up as Antr&AOQ-ge-nfdtest, so precomposed, and the clients show it correctly.
Thanks everyone for the help!
Kind regards, Jan