220 myhost.test.ex ESMTP Exim x.yz Tue, 2 Mar 1999 09:44:33 +0000 250-myhost.test.ex Hello CALLER at a.b.c.d 250-SIZE 52428800 250-8BITMIME 250-PIPELINING 250 HELP 250 OK 250 Accepted 354 Enter message, ending with "." on a line by itself 550-Verification failed for <CALLER@test.ex> 550-custom message 550 message="Sender verify failed" 221 myhost.test.ex closing connection