I use roundcube to fetch emails from different accounts. Now I need to view the emails from local IMAP server on different pcs. But I need to see marked as read the ones I red on that pc only. How to?
you cannot do that. one of the main advantages of IMAP over POP3 is that the mailbox content is the same everywhere.
Is there a way to use two different imap accounts that point to the same emails?
Not sure what you're trying to accomplish. Doesn't seem like a Roundcube question.
If your IMAP server is Dovecot you might start here: http://wiki.dovecot.org/SharedMailboxes