Different SMTP results, same dialogue

[Hobbit User]

Checking two SMTP servers through an ssh tunnel.  They both respond
identically if I imitate the bb-services dialog using telnet, but give
different Hobbit display results.

[root at bump02 hobbit]# telnet 127.0.0.218 25
Trying 127.0.0.218...
Connected to 127.0.0.218 (127.0.0.218).
Escape character is '^]'.
220 SMTP ESMTP
mail
501 5.5.2 Syntax error in parameters scanning ""
quit
221 2.0.0 p1ie.pen.k12.va.us closing connection
Connection closed by foreign host.

But Hobbit shows:

Service smtp on p1ie is not OK : Unexpected service response
554 p1ie.pen.k12.va.us ESMTP not accepting messages
550 5.0.0 Command rejected
221 2.0.0 p1ie.pen.k12.va.us closing connection

and gives a yellow ball.  Next,

[root at bump02 hobbit]#  telnet 127.0.0.206 25
Trying 127.0.0.206...
Connected to 127.0.0.206 (127.0.0.206).
Escape character is '^]'.
220 SMTP ESMTP
mail
501 5.5.2 Syntax error in parameters scanning ""
quit
221 2.0.0 pen3.pen.k12.va.us closing connection
Connection closed by foreign host.

And Hobbit shows:

Service smtp on pen3.pen.k12.va.us is OK (up)
220 SMTP ESMTP

and gives a green ball.  I know tunneling is not the standard practice,
and I'm not sure why Hobbit has an incomplete RFC2821 command as part of
its test ("mail" is invalid by itself), but with identical responses, I'd
expect the same results on the monitor matrix.  What am I missing?