switching from pop3 to imap on thunderbirfd

[oxy]

hi all,

look what i did:

1) config pop3 account to stop checking new email
2) create a new imap account: it was created by default using the same
local folder as the pop3 account. Thus all recent email was there.
3) change local folder of pop3 account to sth different (eg
~/.thunderbird/old_pop3)

The new account works fine but i cannot access older email of the
mailboxes that it inherited from the pop3 account. I tried to
reconfigure the local folder of the older pop3 account in hope of
accessing these older msgs but the system refuses.

Any idea?

thx...
thunderbird  38.2.0 /   ubu 14.04