[comp.unix.aix] sendmail.cf - solution was OK mx

RRH@vm.nrc.ca (04/22/91)

Thanks to all who responded so fast. The solution was to set
the OK MX or OK ALL. I chose to use the MX.

Thanks once again.

bware@slate.mines.colorado.edu (Bob Ware) (04/23/91)

In article <1991Apr22.153437.23361@nrcnet0.nrc.ca> RRH@vm.nrc.ca writes:
>Thanks to all who responded so fast. The solution was to set
>the OK MX or OK ALL. I chose to use the MX.
>

You may want to use "OK ALL" rather than "OK MX".  Or perhaps:
"OK MX ANY".

We ran into problems with a few hosts when we had "OK MX" set.  Without 
"ANY" set, the system searches up the domain ladder for a CNAME record
before it looks for an MX record.  Consequently, if you have a duplicate
name in a "parent" domain and that name has a CNAME record, you may get
the wrong host.  For example:

1. "pikes.mines.colorado.edu." and "pikes.colorado.edu." both exist.  
2. "pikes.colorado.edu." has a CNAME record.
3. In the above case, if you login into an RS/6000 that has "OK MX" set,
for example: "hope.mines.colorado.edu.", and execute: 

"mail pikes"

the mail goes to the "pikes.colorado.edu" CNAME pointer rather than to
pikes.mines.colorado.edu.

Apparently, you don't see this on most other Unix systems, because
they have the "ANY" bit hardwired into sendmail.  The RS/6000 gives
you a choice.

IBM level 3 support sorted this out for us (thanks IBM).

-- 
Bob Ware, Colorado School of Mines, Golden, Co 80401, USA
(303) 273-3987
bware@mines.colorado.edu bware@slate.mines.colorado.edu bware@mines.bitnet