gnus-message-archive-group does not work when I compose-mail

Hello,

I am using an nnimap method, and I have set

--8<---------------cut here---------------start------------->8---
(gnus-message-archive-group "[email protected]:Sent")
--8<---------------cut here---------------end--------------->8---

Additionally, I set the gcc-self value:

--8<---------------cut here---------------start------------->8---
  (gnus-parameters
   '((".*"
      (gcc-self . "[email protected]:Sent")
      (gnus-use-adaptive-scoring nil)
      (auto-expire . nil)
      (total-expire . nil))))
--8<---------------cut here---------------end--------------->8---

When I respond to an email in [email protected]:INBOX, gnus
automatically addes a Gcc header. This is the intended
behavior. However, when I C-x m (compose-mail), no Gcc header is added,
and my sent email is lost.

Any idea why this is the case, and why both gnus-message-archive-group
and gcc-self are not working as expected?

Husain