I am currently looking at migrating a small (under 50 employees) business email from Yahoo Small Business to Zoho Mail Lite.  I would like, if possible, to keep the email addresses the same, and import all messages and contacts over with a minimum of fuss.  Currently, our YSB address shares a server IP address with a company in South America that is suffering a malware problem, leading our email IP address to show up on several blacklists.  I am hope a transfer will solve these problems!  If necessary, reissuing emails with a new domain name will also be acceptable.  Any suggestions?