carl@CITHEX.CALTECH.EDU (08/16/86)
I seem to recall seeing, sometime in the past year, mention of a problem with mailing lists, in which mail failed if there were addresses on remote nodes specified in the list which referred to unknown users. Does anybody out there remember seeing the item (and have a copy of it or a recollection of its details)? More important, does anybody know if DEC is aware of the problem (it crops up, for example, when sending mail between a VMS system and one running ULTRIX), and if so whether they've got any idea when it will be fixed? Thanks in advance.
LEICHTER-JERRY@YALE.ARPA (08/19/86)
I seem to recall ... mention of a problem with mailing lists, in which
mail failed if there were addresses on remote nodes specified in the list
which referred to unknown users. Does anybody out there remember seeing
the item...? More important, does anybody know if DEC is aware of the
problem (it crops up, for example, when sending mail between a VMS system
and one running ULTRIX), and if so whether they've got any idea when it
will be fixed?
The only problem I know of that sounds at all like this is one I described on
this list a couple of months back: If a forwarding address expands to mul-
tiple recipients, and one or more of those recipients are unreachable for any
reason, sending to the forwarding address will not generate "sufficient" error
messages.
That is: Suppose VAX B has an POSTMASTER account. We log in to POSTMASTER on
VAX B, go into MAIL, and do a SET FORWARD @POSTMASTERS. In the POSTMASTER
SYS$LOGIN account is a POSTMASTERS.DIS file containing multiple addresses.
Mail sent to B::POSTMASTER will be forwarded correctly as long as ALL the
addresses listed in POSTMASTERS are reachable. If any are not, the error
reported will only report the FIRST list member who could not be reached, not
all of them; in fact, there will be no indication that the list contains any
other members. Now suppose the first unreachable member of the list was
unreachable because his account had been removed. The sending mailer will
get back a single "no such user" error message, and will abandon attempts to
retry the mail later - although other list members might be reachable. (Ac-
tually, as long as the unknown user remains on the forwarding list, it will
remain impossible to forward through that list - all attempts will get the
same message. MAIL will not attempt to forward to SOME of the members of the
list while not forwarding to others.)
Note that the problem:
a) will not occur when mail is being sent to a local address. For local
messages, the sending MAIL is also the delivery agent, and expands any for-
warding addresses itself. It treats a forwarded-too mailing list just like
a mailing list specified directly on the "To:" line, and asks you whether to
deliver to the reachable members of the list.
b) does NOT require that members of the mailing list be on remote nodes; it
is just more likely to occur when they are, because users on the same node as
the mailing list are almost always reachable when the mailing list itself is.
This problem is inherent in the MAIL-11 protocol, which doesn't provide any
method for reporting multiple failures, or in general multiple statuses (some
failures and some successes.)
I would not bet on this ever changing. MAIL-11 is an old, very simple, very
limited protocol. The future is with standards like X.400 - which other DEC
mail products support. (Sold seperately. Batteries not included.)
-- Jerry
-------CHAA006%vaxa.rhbnc.ac.uk@CS.UCL.AC.UK (08/20/86)
I tried to make MAIL fail in the way you outlined, but all appeared to
work if I answered "Y" to MAIL's question "send anyway ?". ** Phil.
Philip Taylor (Royal Holloway and Bedford New College; Univ. of London; U.K)
Bitnet/NetNorth/Earn: chaa006@vaxa.rhbnc.ac.uk (or) chaa006%rhbnc.vaxa@ac.uk
(or) : chaa006@vaxb.rhbnc.ac.uk (or) chaa006%rhbnc.vaxb@ac.uk
Arpa : chaa006%vaxa.rhbnc.ac.uk@ucl-cs.arpa
(or) : chaa006%vaxb.rhbnc.ac.uk@ucl-cs.arpa