Sendmail problems: FreeFormName

[Paul-Andre Pays]

Help needed with sendmail!

We are having troubles with sendmail.

ENVIRONEMENT:
             (192.31.211)
               	 |
   [X.25]====mars+
               	 |
               	 +cambur---kiwi---cerise---...---(192.54.156)
               	 |
               	 |
               	 +moon
               	 |
               	 +logia
               	 |
               	 +sonia
               	 |

moon:	SUN 3/160
logia, sonia:	3/50s diskless served by moon

cambur:	SS1
kiwi, cerise, :  SS1 dataless served by cambur

mars: SUN 3/60

All SUN systems are running SunOS 4.0.3.

mars is mainly used for running M.PLUS which is an X.400 router AND an
RFC-987 gateway (RFC-X400 converter) Thus, mars is acting as the master
mail site, and all other machines are running sendmail with a 'subsidiary'
form of sendmail.cf

The mailboxes
	for cambur, kiwi, cerise,... are managed by cambur
	for moon, sonia, logia,... are managed by moon.

For X.400 specific services (eg. fax from e_mail service) we need to use a
FreeFormName for the recipients of some messages.

And here is the problem (put in evidence by use of mailx): when sending a
message (under Mail) by & m aFreeFormNameString<foo at subd1.subd2.topd>

1. IF generated from "moon" or "cambur"
	THEN everything is OK, mail is generated
	and received OK by either an internal user of any machine within emse
			or external X.400 recipient (with appropriate FFName)
2. IF generated from any "secondary" machine (eg "kiwi", "cerise", "logia"...)
	THEN bug!!!!!!
	the message transfer between kiwi and cambur (or sonia and moon)
	  BLOCKS; sendmail processes remain pendant and even
	  replicate after some time-out (raising load up to panic abort)

Note: messages without a FreeFormName for a recipient are transfered and
delivered without any problem.

QUESTIONS: 

1. Why messages (with or without FFName) issued from "secondary" machine
are transfered through the respective "server" (eg from "kiwi" to "moon" a
message passes through "cambur", whereas it could perfectly be sent
directly to "moon")? (all machines and networks are known from every site
-through YP-) this is strange to me, but non blocking.

2. (worse) Why messages including a FFname are processed correctly when
issued from servers ("moon" or "cambur") whereas the same messages issued
from diskless or dataless machines (eg "kiwi" or "logia") block?

We suspect that this is due to sendmail.cf, but feel completely helpless
to solve it.  Has someone any clue or advice?

-- PAP