Finding remembered passwords

Hi,

I am using Mozilla 1.7.12 under Linux.  Today two of my email accounts
are playing up, both using POP3 and the same provider.  With one of
them, using their web mail interface works fine because I have done it
before and the password manager knows the password.

The problem is with the other one.  I normally read and write mails on a
daily basis using the stored password, unfortunately I cannot remember
what that password is and it seems that the password manager does not
know either.

Does anyone have a clue how and where the send/receive passwords are
stored?  Do I need to set up a sniffer to see what I am sending to that
site?

What lulled me into a false sense of security was that the password
manager has several passwords stored where the site-name starts with
'mailbox://' or 'smtp://'.  For some arcane reason that one account is
not there.  The other one is, with the correct password that I can use
for their web mail interface.

All very stupid :-)

Thanks, Andrew