220 ESMTP
EHLO myhost.test.ex
250 OK
-MAIL FROM:<CALLER@myhost.test.ex>
+MAIL FROM:<eximtest@myhost.test.ex>
250 Sender OK
RCPT TO:<userx@domain.com>
250 Recipient OK
550 Not here, mate
HELO myhost.test.ex
250 OK
-MAIL FROM:<CALLER@myhost.test.ex>
+MAIL FROM:<eximtest@myhost.test.ex>
250 Sender OK
RCPT TO:<userz@domain.com>
250 Recipient OK
220 ESMTP
EHLO myhost.test.ex
250 OK
-MAIL FROM:<CALLER@myhost.test.ex>
+MAIL FROM:<eximtest@myhost.test.ex>
250 Sender OK
RCPT TO:<usery@domain.com>
250 Recipient OK