I assume you’re attempting to fill in the mailhost input parameter of the pub.client:smtp service. And that you’re trying to determine a particular smtp host to connect to based on the addresses that will be in the to parameter.
The good news: you don’t need to do that. You most likely won’t have permissions to connect to an SMTP host directly, and keeping track of credentials to use for multiple SMTP hosts would be an unnecessary pain.
Just specify the SMTP host within your company (or your client’s company) and send the mail with whatever to addresses you desire. The SMTP host will take care of the rest.
But to really answer your question directly: “how to determine the SMTP host name from an e-mail address domain name”. There is no way to reliably determine an SMTP host from a domain name.
#Integration-Server-and-ESB#webMethods#webmethods-Protocol-and-Transport