550 failure message\r
250 Reset OK\r
250 OK\r
-451 Temporary local problem - please try later\r
+451 defer message\r
250 Reset OK\r
221 the.local.host.name closing connection\r
220 the.local.host.name ESMTP Exim x.yz Tue, 2 Mar 1999 09:44:33 +0000\r
550-Rejected after DATA: could not verify "From:" header address\r
550 bad@domain: Unrouteable address\r
250 OK\r
-451-could not connect to V4NET.0.0.0 [V4NET.0.0.0]: Network Error\r
+451-Could not complete sender verify callout: V4NET.0.0.0 [V4NET.0.0.0] : Network Error\r
451-Could not complete sender verify callout for <callout@x>.\r
451-The mail server(s) for the domain may be temporarily unreachable, or\r
451-they may be permanently unreachable from this server. In the latter case,\r