sending email in specific domain..........

[toton]

Hi,
I have an application which sends emails for survey.These emails are coming from a particular table in database.Within that table email column consist several emails with different domains.
Ex:[e-mail],[e-mail],[e-mail] etc.
now I have to send emails only in @xyz.com and @abc.com
but not in the @def.com.
Can any body help me in vb.net.
I can do this from Query through Like operator...but my requirment is I have to mention all this domain in Web.config.so that we can add or delete in the future easily...........what is the process of picking from Web.config file and comma separated it and putting in Query in that particular page.............
it will be great if I get help in Vb.net..............