e-Newsletter 2.0.4 bounce settings not working

Hi, I've tried a number of things, but still get an error message. Uninstalled 2.0.4 and reinstalled 2.0.4; changed from SSL to non-SSL; used alternate ports; confirmed passwords; double checked server names; no luck.

Error message:

<b>Warning</b>: imap_open() [function.imap-open]: Couldn't open stream {pop.1and1.com:110/pop3/notls/novalidate-cert/norsh}INBOX in <b>/homepages/29/d195314921/htdocs/abbottrun.org/dev/wp-content/plugins/e-newsletter/e-newsletter.php</b> on line <b>1560</b>
Can't open mailbox {pop.1and1.com:110/pop3/notls/novalidate-cert/norsh}INBOX: invalid remote specification

Website hosted through 1and1.com - do know they prefer customers to use imap rather than pop3.

Any assistance would be appreciated.