[VM] FCC for sent messages - how to merge into INBOX?

[Diagon]

Hi.

I'm trying to get myself settled into VM, but am having one problem for which I 
hope I might get some help.  I have two imap folders in my vm-spool-files that 
dump into my INBOX, deleting the messages on the server immediately on 
download.  That works fine.  To handle sent messages, I would like to use an 
FCC line in my mail header, to avoid sending them up to the server and back 
down again.  

(1) I tried FCC'ing directly into the INBOX, but that didn't work.  The message 
would get in there, which I could see by visiting the INBOX folder literally 
(find-file-literally), but it would not show up on the VM INBOX Summary.  After 
a few operations with other messages, those "hidden" sent messages would just 
disappear from the INBOX.

(2) So I tried FCC'ing into a SENT folder, and then using "C-u g" to grab the 
messages in that folder.  That didn't work either, as it complained that the 
folder SENT was not the same type as INBOX (the latter is babyl).  

(3) Finally, I tried to add SENT as one of my vm-spool-files and grab it with 
"g", but while that would copy the messages into INBOX and delete them from 
SAVE, they would again not show up in Summary, even though visiting INBOX 
literally shows the messages in there.

On the other hand, if I just visit the SENT folder, I can save the messages to 
INBOX, and everything works fine.

Any thoughts on how I should approach this?

Thanks /D

I'm using VM 8.1.2 on emacs 24.5.1 on Ubuntu 16.04.