Received: from CALLER by the.local.host.name with local (Exim x.yz) (envelope-from ) id 10HmbB-0005vi-00 for mmdf_userz@test.ex; Tue, 2 Mar 1999 09:44:33 +0000 Date: Tue, 2 Mar 1999 09:44:33 +0000 Message-Id: From: CALLER_NAME Test message with mmdf_ prefix   Received: from CALLER by the.local.host.name with local (Exim x.yz) (envelope-from ) id 10HmbC-0005vi-00 for userz@test.ex; Tue, 2 Mar 1999 09:44:33 +0000 Date: Tue, 2 Mar 1999 09:44:33 +0000 Message-Id: From: CALLER_NAME Second test message, no prefix.   Received: from CALLER by the.local.host.name with local (Exim x.yz) (envelope-from ) id 10HmbD-0005vi-00 for userz@test.ex; Tue, 2 Mar 1999 09:44:33 +0000 Date: Tue, 2 Mar 1999 09:44:33 +0000 Message-Id: From: CALLER_NAME Second test message, no prefix.