Have the new isp set up the dns records with the current entries (mx, etc...) before you switch ISP's and dns servers. Then when your ready to change ip's just call the new isp and have them change it for you to the new ip's. Do you have a 2nd mx record to spool email with? If so no worries it should send email to your new ip when the dns cache (TTL) has expired or when port 25 is available. Hope this helps Joe