Bugs in rmail?

[Shane P. McCarron]

I have been handling a few local mailing lists that discuss various
projects, and they have been getting larger and larger. They way I
handle a message is that I send the message individually to each
person on the list. Recently, I noticed that the volume for this was
pretty high, and that a number of the messages all followed common
paths for some of their route. I had also noticed that the smail
program (which was recently posted to the net) would group messages
that were going to the same site together, so that only a single file
is sent.

Consequently, I modified my mailer script to do a:
mail `cat users` < file

This worked as you would expect from my previous paragraph, routing
mail to the correct machines and such. Unfortunately, one of the
downstream sites choked on this. It seems that his mailer (rmail)
can't handle more than one destination. These X. files would attempt
to execute, blow off and exit.

My question is: Is this a wide spread problem? I know that I can fix
it on this particular site, since it is in the same building I am in,
but am I going to cause problems for EVERYONE on my mailing list if I
go back to this simpler, more efficient scheme?
--
Shane P. McCarron UUCP ihnp4!meccts!ahby
MECC Technical Services ATT (612) 481-3589

"They're only monkey boys; We can still crush them here on earth!"

[John Gilmore]

I made a similar change to the Sun sendmail, which I believe has survived
into the 4.3BSD sendmail. (You need to turn it on in sendmail.cf, as
explained below.) If multiple recipients of a message are at the same
host (or the next hop in the path is the same), your system will only
send one copy of the message, and run an "rmail user1 user2 user3..."
command via uux. I asked around at the time, how likely this was to
break things, and the response was that the command line would likely
have a length limit around 512 bytes, but that was all.

Since then I have heard it rumored that the "rmail" programs in V7 and
4.1BSD will not accept multiple arguments. However, I have 38 mail
links and no mail is getting lost, so I must not be talking to any V7
or 4.1BSD sites. (Utzoo doesn't count, that's only the ghost of
V7 yet-to-come.)

Here's how you turn on the feature in Sun or 4.3 /usr/lib/sendmail.cf.
It's a text file which you can edit to configure your mailer.
There is a short section that defines the uucp mailer. It starts
with a line with "Muucp" at the left margin, e.g. like this:

Muucp, P=/usr/bin/uux, F=sDFMhuU, S=13, R=23,
A=uux - -r $h!rmail ($u)

This says that mail resolving to a "uucp" address should run program
/usr/bin/uux with various flags, various arguments, and various rules for
munging the to and from addresses.

You have to add the "m" flag, which says "multiple recipients OK to
send out via this mailer", and specify the maximum argument length. I
use 250 because it's a lot less than 512. (By the way, the L= value
does NOT count the chars that are explicitly specified in the A=
parameter; it only counts the characters of the recipients' addresses.)
It looks like this:

Muucp, P=/usr/bin/uux, F=sDFMhuUm, S=13, R=23, L=250,
A=uux - -r $h!rmail ($u)

After editing in the change and writing the file back (you'll need to
be root to do this), run "sendmail -bz" which will "compile" the new
configuration into a binary file which is fast to run with.

This causes the eventual command used if you mail to sun!avb and sun!wnj
to be:

uux - -r sun!rmail avb wnj

This is especially useful if you send out a large mailing list, or are
a relay point for such a site. Gateways to SMTP based networks would also
be helped by having this fix.
--
John Gilmore {sun,ptsfa,lll-crg,ihnp4}!hoptoad!gnu jgil...@lll-crg.arpa
May the Source be with you!