[Date Prev][Date Next] [Thread Prev][Thread Next] [Date Index] [Thread Index]

Re: mail basics on a debian system

On Tue, Dec 10, 2002 at 01:56:08PM +0100, Robert Land wrote:
| I'm not very experienced with unix/linux and would
| appreciate some information on the mail topic.
| I have this one box system, using my general account
| 'rland' and sometimes root for system configuration.
| What I would like to know is if/how rland recieves mail
| actually ment for root, because I rarely do a root shell
| login. I couldn't find anything in the mail man page and
| /etc/mail.rc has nothing looking like "root:rland", only
| /etc/aliases created by eximconfig has these entries
| which to my understanding forwards all mail to postmaster
| and root to me which is 'rland'.

I don't know what /etc/mail.rc is from.  exim doesn't use it.  exim
does use /etc/aliases to route messages.

| What I'm realy unsure about is if _all_ mail, even the one
| sent by the lowlevel 'mail' program goes through port 25.

No.  Many unix programs use a local pipe to deliver mail (eg mail,
mutt, cron and others).

| If yes, then exim should do all the work and all program/system
| messages sent to root should reach me with the help of exims
| /etc/aliases file.

This is correct.  All MTAs have two interfaces -- an SMTP one and a
sendmail one.  The SMTP one typically involves TCP port 25.  It is how
mail is moved from one machine to another.  The "sendmail" interface
involves opening a pipe to /usr/bin/sendmail and writing the message
itself directly to the pipe.  Regardless of which interfce the MTA
(exim on your system) receives the message it follows the same process
in determining where to deliver it.  The end result is that yes
/etc/aliases is sufficient to redirect mail destined for one user to

| Is this correct and how can I generate a system failure which would
| cause a root mail to test this.

Just send a message (using mutt or any other mail client) to


I can do all things through Christ who strengthens me.
        Philippians 4:13

Attachment: pgpe3fVU5P3jb.pgp
Description: PGP signature

Reply to: