Configure SMTP to receive mails and how to determine smtp host name from domain name

I am trying to send a mail and read a mail. Here are the questions I have.
I have used the service pub.client.smtp to send a mail. I am successfully able to send a mail when I give username/password(my account username and password on target mail server), target smtp host name. I used the mail server that I am aware of . But if I have to send a mail to outside servers then that would be difficult. So can someone tell me if there is a way to determine the smtp server name from a given domain name. I have searched in net, most of the people are suggest to use either mail.domainname or smtp.domainname but sometimes these two are not working. Also should I pass the username/password always ?

My question regarding receiving a mail…I am not sure how to configure a port for receiving the mail.I have yet to kick start the service for receiving a mail. Can some one help me do that ?

Thanks in advance.

Pls refer “webMethods_Integration_Server_Administrator’s_Guide” for configuring email listener port…


Configure IS to use just one SMTP server. Typically this will be your company’s SMTP host, MS Exchange Server, Lotus Domino server, etc. That server will relay mail to outside SMTP servers as needed to deliver mail to the recipients specified in a given e-mail.