mailcnfg(4) FILE FORMATS mailcnfg(4)
NAME
mailcnfg - initialization information for mail and rmail
DESCRIPTION
The /etc/mail/mailcnfg file contains initialization informa-
tion 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 invoca-
tion 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 over-
ride any specification of DEBUG in
mailcnfg.
CLUSTER To identify a closely coupled set of
systems by one name to all other sys-
tems, 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 direc-
tory 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. Typi-
cally 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
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mailcnfg(4) FILE FORMATS mailcnfg(4)
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 depo-
sited in the local 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 sub-
directory 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 avail-
able, and then sent there for delivery.
DELEMPTYMFILE If not specified, the default action of
mail and rmail is to delete empty mail-
files if the permissions are 0660 and to
retain empty mailfiles if the permis-
sions 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 com-
mand 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 nota-
tion for long strings (such as
/usr/lib/mail/surrcmd) which may appear
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mailcnfg(4) FILE FORMATS mailcnfg(4)
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
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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