Here you have to choose, whether the mails are passed on to the mail system or the mail client and if so, in which way. Please see "Client Connections"
For mail clients that use the "MAPI"-interface
Delivery via ixi-UMS SMTP Client directly to the mail server / ixi-UMS Business Server. In a next step, you have to enter the IP-address of the mail server or the ixi-UMS Business Server as well as the e-mail address of the sender.