[Dovecot] Change/add mail header via IMAP

[Алексей Сундуков]

Hello.

I create RoundCube plugin and I have question. I want add mail header
and I see 2 way:

1) change file via filesystem (mailbox in maildir format);
2) change header via dovecot.

I think 1) bad way. But I do not know dovecot support change head
information or not? My by via IMAP commant? same programm (LDA?)? May
be it impossible via dovecot?