Configure sendmail for SMTP relay with your ISP
2009-09-26
709 words
4 mins read
http://cri.ch/linux/docs/sk0009.html
I have copied the document from the above link without modifications
Author: Sven Knispel
Updated: 05-01-2005
Feedback welcome: <a href="mailto:linux@cri.ch">linux@cri.ch
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The following article explains the setup of sendmail for forwarding mails to your ISP’s smtp server.
It is assumed that you have sendmail up-to-date and configured properly.
_Note: this setup does not work properly for smtp-server using
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SASL
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(e.g. like
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smtp.pobox.com
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)
Most of the commands must be executed with the corresponding rights (using
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sudo
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).
1. configure your smtp-server
(this requires that you have the package
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sendmail-cf
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installed)
1.1. changes to
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/etc/mail/sendmail.mc
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Uncomment the definition
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SMART_HOST
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and add the correspondign
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FEATURE
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to it:
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define(`SMART_HOST\', `your-smtp-server\')<br /> FEATURE(authinfo)dnl
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Note: Please note, that these are ”oriented” quotes.
1.2. create the new
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sendmail.cf
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Stop sendmail by issuing the command
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/sbin/service sendmail stop
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and log on as
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root
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to issue this command.
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m4 /etc/mail/sendmail.mc > /etc/mail/sendmail.cf
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1.3. Define the account information for connecting to the smtp-server
Edit/create
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/etc/mail/authinfo
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and add the following line:
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AuthInfo:<your-smtp-server> "U:<your-smtp-user>" "P:<your-smtp-password>" "M:DIGEST-MD5"
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_Note:_The
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M:
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may vary depending on the capabilities of the smtp-server (e.g.
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CRAM-MD5, PLAIN
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).
Create
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authinfo.db
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:
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makemap hash /etc/mail/authinfo < /etc/mail/authinfo
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and finally restart sendmail:
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/sbin/service sendmail restart
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1.4. Configure header rewriting (optional)
Header rewriting consists in replacing the
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From:
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and
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Reply to:
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in the header of an outgoing mail in order for the recipient to reply to a valid address.
This can be set by editing the file
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/etc/mail/userdb
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:
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<local-name>:mailname <email-adsress>
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E.g.:
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# /etc/mail/userdb <br /> sven:mailname sven@foo.org
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Finally create the corresponding database:
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makemap btree /etc/mail/userdb.db < /etc/mail/userdb
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… and finally restart sendmail:
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/sbin/service sendmail restart
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1.5. Test your settings
Issue following commands and check the trace for verifying the delivery path:
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/usr/sbin/sendmail -bv root@localhost
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Should show a ”local” delivery.
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/usr/sbin/sendmail -bv <your-mail>@<your-domain>
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Should show a delivery path through your ISP.
For troubleshooting you should check the mail-log:
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/var/log/maillog
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2. Forwarding
Forward can be defined in
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~/.forward
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. (just enter the e-mail addressto forward to). _Note:_The permissions of that file must be adjusted correspondingly in order to avoid sendmail ignoring it (see
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/var/log/maillog
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in case of problems).
3. References
For further information I recommend to check following link:
- <a linkindex="3" href="http://www.pl-berichte.de/work/server/mailserver.html">http://www.pl-berichte.de/work/server/mailserver.html
- <a linkindex="4" href="http://www.sendmail.org/%7Eca/email/auth.html">http://www.sendmail.org/~ca/email/auth.html
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Authored By Amit Agarwal
Amit Agarwal, Linux and Photography are my hobbies.Creative Commons Attribution 4.0 International License.