Some Handy Tools

1) To check exchange connectivity


https://www.testexchangeconnectivity.com/


2) To validate SPF record


http://www.microsoft.com/mscorp/safety/content/technologies/senderid/wizard/


3) DomainKeys Checker


http://www.mailradar.com/domainkeys/


4) SSL checker 


http://www.sslshopper.com/ssl-certificate-tools.html