Connection to send e-mail goes wrong

[Cecil Westerhof]

I have the following in my .gnus:
    (setq gnus-message-archive-group
          '((if (message-news-p)
            "INBOX.Verzonden.misc-news"
          (concat "INBOX.Verzonden." (format-time-string "%Y-%m")))))

In this way every send e-mail (not newsgroup message, maybe I should do
that also) is archived pro month. Until recently my only problem was
that I had to add the new mailbox every month to my installation.

But that has changed. In my group buffer I have for example:
         *:*nnimap+e-mail:INBOX.Verzonden.2010-03
         0: nnimap+e-mail:INBOX.Verzonden.2010-01

The second one is no problem. The first one looks the same, but is not.
When trying to open it, I see in *Messages*:
    Opening nnimap server on e-mail+nnimap+e-mail:INBOX.Verzonden.2010-03...
    Denied server nnimap+e-mail+nnimap+e-mail:INBOX.Verzonden.2010-03
    Opening nnimap server on 
e-mail+nnimap+e-mail:INBOX.Verzonden.2010-03...failed

While when I open 2010-01 I get:
    Retrieving newsgroup: nnimap+e-mail:INBOX.Verzonden.2010-01...
    nnimap: Updating info for nnimap+e-mail:INBOX.Verzonden.2010-01...done
    Fetching headers for nnimap+e-mail:INBOX.Verzonden.2010-01...done

So for one reason or another I get extra information appended to the new
folders. Anyone an idea what is happening and what to do against it?

Could a solution be changing active and local in agent.lib? If so: how?
Where are those files documented?

-- 
Cecil Westerhof
Senior Software Engineer
LinkedIn: http://www.linkedin.com/in/cecilwesterhof