e-newsletter not working suddenly


I seem to have developed issues with e-newsletter on several sites. I have tried as much as I can find in the forums but with no success.

Firstly, the bounce email no longer seems to be connecting giving error on test

Warning</b>: imap_open() [function.imap-open]: Couldn't open stream {mail.schoolinformer.com:110/pop3/notls}INBOX in <b>/home/schoolin/public_html/wp-content/plugins/e-newsletter/email-newsletter-files/class.functions.php</b> on line <b>1619………

Also, whilst the smtp settings seem to be testing fine on this domain, on another, I am unable to get a successful test despite trying every possible combination of smtp settings and even duplicating from one that is working.

This error is

Failed to send test email! - Please check your outgoing email settings and server config to see if selected ports are open. Error details: The following From address failed: newsletter@oldewtermill.co.uk : Called Mail() without being connected

Any ideas - it was working fine previously