After switching the customer from Windstream to WOW for there SIP trunks , the voicemail to email has stopped working. Any ideas ? Nothing has changed except the SIP trunk provider . I have the phones set to delete after it sends the voimail to email and it will delete but never get a email , we have checked there spam filter nothing there. If i go to the SMTP settings and do a test email i get SMTP failed please check credentials and try again. HELP