Added two more POP3 tests

tests/data/test812

@@ -0,0 +1,45 @@
+<testcase>
+<info>
+<keywords>
+POP3
+RETR
+FAILURE
+</keywords>
+</info>
+
+#
+# Server-side
+<reply>
+<servercmd>
+REPLY RETR -ERR no such message
+</servercmd>
+</reply>
+
+#
+# Client-side
+<client>
+<server>
+pop3
+</server>
+ <name>
+POP3 RETR invalid message
+ </name>
+ <command>
+pop3://%HOSTIP:%POP3PORT/812 -u user:secret
+</command>
+</client>
+
+#
+# Verify data after the test has been "shot"
+<verify>
+<errorcode>
+56
+</errorcode>
+<protocol>
+USER user
+PASS secret
+RETR 812
+QUIT
+</protocol>
+</verify>
+</testcase>