SmartPOP2Exchange does not automatically read all folders of an IMAP account. But you can create accounts in SmartPOP2Exchange for each folder of your IMAP server.Like:Account 1:
Mailbox: INBOXAccount 2:
Mailbox: INBOX/SUBFOLDERAccount 3:
Every server has a maximum count for 'hops ' of an mail. (hop count = count through how manyservers a mail was send). Usually that maximum is not reached. But when it 'sreached the server either bounces that mail or does not accept it. So your ExchangeServer does not accept it because it already passed too much SMTP servers.
Check your accepted domains in the settings of your Exchange Server. If one of them is set to "Relay" change it to "Authoritative".
There is not official way to move an existing POP3/IMAP account to another existing SMTP.
We suggest to clone/duplicate the entire account, change the SMTP senders address as desired and disable the original SMTP account.