Plesk 10.4 SMTP Problem on Windows Server 2008

I've to resolve this issue for my Dedicated Server.  I've 1and1 dedicated hosting server with windows 2008 R2 and plesk 10.4 running on it. I've setup IP's and subdomains on 1and1 server with 2 different IP's. I am having problem in sending emails to some of the mail servers. When I look SMTP settings in some websites like mxtoolbox it gives me the following error with SMTP settings. "Warning - Reverse DNS does not match SMTP Banner" want a solution for this issue ASAP. I know its a maximum of an hour's work for an experienced individual who knows what he's doing. Thanks.