In the mail system group described here, an SAP System is linked to an external mail system (for example, Microsoft Exchange or Lotus Domino). Other SAP Systems can also be integrated. All users in the mail system group have home mailboxes in the external mail system. There, they receive all messages that are sent to their addresses in the SAP System or in the external mail system (internally or externally).
The link between an SAP System and an external mail system is made by a connector (for example SAP Exchange Connector or Lotus Domino MTA for R/3). Messages are exchanged between the SAP System and the mail system using the communication method SMTP (Internet mail). The communication methods SMTP and FAX can be used for external communication (from the mail system group).
Internet messages sent from the SAP System to external recipients (outside the mail system group) are first routed to the external mail system and then transferred to the Internet by the Internet mail connector.
In the mail system group described here, two domains are available for internal routing of Internet messages. One is for the SAP System (@SAP.COMPANY.COM) and one is for the external mail system (@COMPANY.COM). Only one domain (@COMPANY.COM) exists for external routing (outside the mail system group). This can be reached if the address is converted by an alias file.
If, in your mail system group, the status of messages sent from the SAP System is not to be returned in the SAP System, you only require one domain. In this case, you do not require an alias file for address conversion. However, you cannot then send Internet messages to the SAP System.
Depending on the system from which they are sent, outgoing faxes are sent using the fax server connected to the SAP System or to the external mail system. Incoming faxes are normally sent directly to the mailboxes of the users in the mail system group using the fax server for the external mail system.
The following diagram illustrates the system structure in which it is possible to return status confirmations to the SAP System when documents are sent within the mail system group: