After deployment of Public Key in your DNS server, you can test your DomainKeys/DKIM by sending an email from your domain to a Gmail or Yahoo email account.
Gmail
Open your email in gmail web mail, click "show details". If there is "signed-by:
your domain", your DomainKeys/DKIM signature is ok.
Yahoo Mail
Open your email in yahoo web mail, if there is
on the left of the sender email address, your DomainKeys/DKIM signature is ok. You
can also mouse over
and see a message " This sender is DomainKeys verified".
<< Set up SPF record in DNS server
See Also
Appendix - Set up SPF record in DNS server
Online DKIM Test Tool
Online DomainKeys Test Tool
Online SPF Test Tool