[plug] email error messages

[Christian]

Colin Muller wrote:

> in /etc/hosts.allow put just this one line:
> ALL: LOCAL, localhost, 127.0.0.
> 
> in /etc/hosts.deny put just this one line:
> ALL: ALL
> 
> Then you can safely leave sendmail and any other daemons you want
> running; this won't affect your ability to fetch mail, surf the Web,
> etc. If you're on a local LAN rather tha a dialup, and want to allow any
> and all connections from that LAN, just put the LAN's first three digits
> in on the pattern of 127.0.0. above.

Be *very* careful.  This assumes that either the service is running from
inetd with the tcpd wrapper (not usually the case with sendmail) OR that
the program has been linked against libwrap.  The sendmail in your
distribution quite possibly is linked against libwrap (use ldd to check)
but, then again, it may not be (the Debian version appears not to be and
the Debian Postfix definitely isn't).  If the program isn't being run
via the wrapper or linked against libwrap then it will take absolutely
no notice of the hosts.allow|deny files.  In this case, the above
settings would provide a false sense of security given that on the
default install of many distributions there are a lot of services
running which do not use tcpwrappers.

Regards,

Christian.