mailcnfg(4) (Essential Utilities) mailcnfg(4)
NAME
mailcnfg - initialization information for mail and rmail
DESCRIPTION
The /etc/mail/mailcnfg file contains initialization information for
the mail and rmail commands. Each entry in mailcnfg consists of a
line of the form
Keyword = Value
Leading whitespace, whitespace surrounding the equal sign, and
trailing whitespace is ignored. Keyword may not contain embedded
whitespace, but whitespace may appear within Value. Undefined
keywords or badly formed entries are silently ignored.
Keyword Definitions
DEBUG Takes the same values as the -x invocation option
of mail. This provides a way of setting a
system-wide debug/tracing level. Typically DEBUG
is set to a value of 2, which provides minimal
diagnostics useful for debugging mail and rmail
failures. The value of the -x mail invocation
option will override any specification of DEBUG
in mailcnfg.
CLUSTER To identify a closely coupled set of systems by
one name to all other systems, set Value to the
cluster name. This string is used to supply the
...remote from... information on the From header
line rather than the system nodename returned by
uname(2).
FAILSAFE In the event that the /var/mail directory is
accessed via RFS or NFS within a cluster (see
CLUSTER above), provisions must be made to allow
for the directory not being available when local
mail is to be delivered (remote system crash, RFS
or NFS problems, etc.). Value is a string that
indicates where to forward the current message
for delivery. Typically this is the remote
system that actually owns /var/mail. In this
way, the message is queued for delivery to that
system when it becomes available. For example,
assume a cluster of systems (sysa, sysb, sysc)
where /var/mail is physically mounted on sysc and
made available to the other machines via RFS or
NFS. If sysc were to crash, the RFS/NFS-
accessible /var/mail would become unavailable and
local deliveries of mail would go to /var/mail on
the local system. When /var/mail is re-mounted
via RFS/NFS, all messages deposited in the local
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directory would be hidden and essentially lost.
To prevent this, if FAILSAFE is defined in
mailcnfg, mail and rmail check for the existence
of /var/mail/:saved, a required subdirectory. If
this subdirectory does not exist, mail assumes
that the RFS/NFS-accessible /var/mail is not
available and invokes the failsafe mechanism of
automatically forwarding the message to Value.
In this example Value would be sysc!%n. The %n
keyword is expanded to be the recipient name [see
mail(1) for details] and thus the message would
be forwarded to sysc!recipient_name. Because
sysc is not available, the message remains on the
local system until sysc is available, and then
sent there for delivery.
DELEMPTYMFILE If not specified, the default action of mail and
rmail is to delete empty mailfiles if the
permissions are 0660 and to retain empty
mailfiles if the permissions are anything else.
If Value is yes, empty mailfiles are always
deleted, regardless of file permissions. If
Value is no, empty mailfiles are never deleted.
DOMAIN This string is used to supply the system domain
name in place of the domain name returned by
getdomainame(3).
SMARTERHOST This string may be set to a smarter host which
may be referenced within the mail surrogate file
via %X.
%mailsurr_keyword As described in mailsurr(4), certain pre-defined
single letter keywords are textually substituted
in surrogate command fields before they are
executed. While none of the predefined keywords
may be changed in meaning, new ones may be
defined to provide a shorthand notation for long
strings (such as /usr/lib/mail/surrcmd) which may
appear repeatedly within the mailsurr file.
Upper case letters are reserved for future use
and will be ignored if encountered here.
FILES
/etc/mail/mailcnfg
/etc/mail/mailsurr
/var/mail/:saved
/usr/lib/mail/surrcmd
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mailcnfg(4) (Essential Utilities) mailcnfg(4)
SEE ALSO
mailsurr(4)
mail(1) in the User's Reference Manual
uname(2), getdomainame(3) in the Programmer's Reference Manual
NOTES
If /var/mail is accessed via RFS or NFS and the subdirectory
/var/mail/:saved is not removed from the local system, the FAILSAFE
mechanism will be subverted.
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