Relaying through Sendmail

I am runnning Sendmail on Redhat 9 and now the boss wants to be able to send mail while he is on a business trip. Currently we allow internal machines to relay based on the allow list.

What is the best method for doing this?

There must be an easy solution without opening the machine to be an open relay which would have us on every black list within 24 hours.

My skill level is self taught and somewhere around novice to some experience.

Any ideas?

As a mail client we use Eudora 5.2 (and some idiots use Outlook.)

Require him to SSH into the machine, and login before he can use it. Should be secure enough.

# Common e-mail tools
sendmail - postfix - sends mail to local users (and internet when configured correctly)
fetchmail - gets mail from internet accounts (non-Hotmail type)
procmail - sorts and delivers into separate mailboxes
mutt - mail client that sucks less than all the others
Email the Linux Way
Suresh Ramasubramanian's email guide
The Linux Mail User HOWTO
The Linux Electronic Mail Administrator HOWTO
SquirrelMail web mail
Why use Hotmail when there is LinuxMail?
Gotmail, a utility to download mail from Hotmail type accounts

A file I found on Suresh Ramasubramanian's email guide:

divert(-1)
dnl This is the macro config file used to generate sendmail.cf
dnl file. If you modify this file you will have to regenerate 
dnl sendmail.cf by running this macro config through the m4
dnl preprocessor:
dnl
dnl        m4 /home/phil/Documents/sendmail.mc > /etc/sendmail.cf <--Change to your path
dnl
dnl You will need to have the sendmail-cf RPM installed for this
dnl to work, if you use an rpm build of sendmail
dnl
dnl include(`../m4/cf.m4')
dnl
dnl If you compile sendmail from a tarball, use the include above.
dnl In this setup, you should create the file as cf/cf/config.mc 
dnl (in the sendmail source tree: eg. /usr/src/sendmail-8.11.6/cf/cf
dnl Now give the command "sh Build config.cf".  Now copy the file
dnl config.cf as /etc/mail/sendmail.cf (please backup first!)
dnl
dnl If you are using the RPM build of sendmail, use the 
dnl include statement given below instead
dnl
include(`/usr/share/sendmail-cf/m4/cf.m4')
define(`confDEF_USER_ID',``8:12'')
OSTYPE(`linux')
undefine(`UUCP_RELAY')
undefine(`BITNET_RELAY')
define(`confCF_VERSION',`dialup-1.3')
define(`SMART_HOST', `smtp.yourisp.com') <--Change this
define(`confAUTO_REBUILD')
define(`confTO_CONNECT', `1m')
define(`confTO_IDENT',0)
define(`confTRY_NULL_MX_LIST',true)
define(`confDONT_PROBE_INTERFACES',true)
define(`confCON_EXPENSIVE',true)
define(`confDELIVERY_MODE', `queued')
define(`PROCMAIL_MAILER_PATH',`/usr/bin/procmail')
define(`ALIAS_FILE',`/etc/mail/aliases')
MASQUERADE_AS(`yourisp.com') <--Change this
FEATURE(`masquerade_envelope')
FEATURE(`smrsh',`/usr/sbin/smrsh')
FEATURE(`mailertable',`hash -o /etc/mail/mailertable')
FEATURE(`virtusertable',`hash -o /etc/mail/virtusertable')
FEATURE(redirect)
FEATURE(always_add_domain)
FEATURE(use_cw_file)
FEATURE(`use_ct_file')
FEATURE(local_procmail)
MAILER(smtp)
MAILER(procmail)
FEATURE(`access_db')
FEATURE(`blacklist_recipients')
FEATURE(`accept_unresolvable_domains')
FEATURE(`accept_unqualified_senders')
dnl FEATURE(`relay_based_on_MX')

# Redhat links
RedHat Linux Manuals
Get your mp3 support here
Maximum RPM
rpmfind
Easier software management: apt4rpm - Red Carpet
RedHat 8.0 Tips & Tricks

# Redhat 7.3 down configuration commands
setup leads to several configuration tools

# Redhat 7.3 up configuration commands
Configure soundcard:
redhat-config-soundcard
Configure X server:
redhat-config-xfree86
Configure network:
redhat-config-network
Manage software:
redhat-config-packages

# Handling NTFS
New Technology FileSystem (NTFS) HOWTOs
Linux NTFS project

Relay his ISP domain

Thanks for the replies.

A few responses with questions.

He can SSH now but he wants to be able to use his eudora or aol account to send the e-mail.

His external or roaming isp is AOL and I will not relay AOL mail... That would be very bad.

Yes I guess I could read all of those how to pages.... but I am totally swamped and do not have the time.

Can I use SSL to do this? I know Eudora has an option for SSL on checking and sending... but I have no idea how to start with the SSL issue. Will that also affect my normal HTTP site? which we someday hope to convert to HTTPS but not yet.

Anyone? Anymore ideas?

Please read my post under SOFTWARE forum.

Google for "POP before SMTP" and DRAC. What happens is when a user "pops" his mail from your unix box the incoming IP address is added to a list similar to /etc/mail/access. This (incoming laptop IP address) will be good for 30 minutes (configurable) and then they'll need to pop again. The downside is that they have to pop to your unix box. If they don't have an account on it you will need to create one for them for just this purpose.

For large networks DRAC is the better option.

http://popbsmtp.sourceforge.net/
http://www.iecc.com/pop-before-smtp.html
http://mail.cc.umanitoba.ca/drac/