First, create reference dates:
touch -d 20210101 /tmp/2021
touch -d 20220101 /tmp/2022
Find and Move messages
find ./ -newer /tmp/2021 -not -newer /tmp/2022 -exec mv -t /home/PATH_TO/Maildir/.Archives.2021.Sent/cur/ {} +
First, create reference dates:
touch -d 20210101 /tmp/2021
touch -d 20220101 /tmp/2022
Find and Move messages
find ./ -newer /tmp/2021 -not -newer /tmp/2022 -exec mv -t /home/PATH_TO/Maildir/.Archives.2021.Sent/cur/ {} +