How do you configure Postfix on SLES11, SLES12, or SLES15 to relay mail to Office365
This document (7023567) is provided subject to the disclaimer at the end of this document.
Environment
SUSE Linux Enterprise Server 15
SUSE Linux Enterprise Server 12 SP3 and higher
SUSE Linux Enterprise Server 11 SP4
SUSE Linux Enterprise Server 12 SP3 and higher
SUSE Linux Enterprise Server 11 SP4
Situation
I need to configure Postfix to relay my mail to Office365, how can I do this ?
Resolution
Assumptions: You have a valid Office365 account e-mail address and password. You are not using "Postfix masquerading". It is also assumed you have a working Postfix configuration and that it can send out mail without a problem.
1. On SLES11, SLES12, or SLES15 have postfix installed and if it is running, shut it down with:
rcpostfix stop
or
systemctl stop postfix
rcpostfix stop
or
systemctl stop postfix
2. On your postfix SLES box cd to /etc/postfix directory as the "root" user in a terminal.
3. Unless you have this file in place already, touch a file called "sasl_passwd", but does not matter the name though, i.e.:
touch sasl_passwd
touch sasl_passwd
4. Edit the file and place this content in it :
[smtp.office365.com]:587 <office365AccountEmailAddress>:office365AccountPassword>
5. Put a blank line at the end of the file
6. Save the file
7. Now compile the /etc/postfix/sasl_passwd file with :
postmap hash:/etc/postfix/sasl_passwd
This will update or create a file called /etc/postfix/sasl_passwd.db, that Postfix will read to know where to attempt to contact office365 with the listed credentials.
NOTE: With SLES 15 SP3, the postfix package has been updated to 3.5.9. Support for "hash" file type has been dropped and a new type of "lmdb" is recommended. Note that this begins with lowercase L. If that is used, the file created above will be named sasl_passwd.lmdb. This information is provided "as is" and has not been specifically tested by the author.
NOTE: With SLES 15 SP3, the postfix package has been updated to 3.5.9. Support for "hash" file type has been dropped and a new type of "lmdb" is recommended. Note that this begins with lowercase L. If that is used, the file created above will be named sasl_passwd.lmdb. This information is provided "as is" and has not been specifically tested by the author.
8. In your /etc/postfix/main.cf put these lines in the file unless already there:
Note: Once you copy the below into your main.cf, make sure you do not have any duplicates of any of these lines
in your file :
############################################################
# Minimum Requirements to get Postfix relay to Office365 to work
# sasl and tls
############################################################
relayhost = [smtp.office365.com]:587
smtp_sasl_auth_enable = yes
smtp_sasl_password_maps = hash:/etc/postfix/sasl_passwd
smtp_sasl_tls_security_options = noanonymous
smtp_sasl_tls_security_options = noanonymous
smtp_use_tls = yes
NOTE: Change the above file's reference of hash to lmdb if lmdb was used in step #7.
9. Save the main.cf changes
10. Make sure you have this in your /etc/postfix/master.cf :
tlsmgr unix - - n 1000? 1 tlsmgr
11. Restart postfix with:
rcpostfix restart
or
systemctl restart postfix
rcpostfix restart
or
systemctl restart postfix
12. Test with sending a test message to verify this works as it did for me, with :
mail -s "This is a test message using Postfix with Office365 relay host" -r <office365AccountEmailAddress> <recipientEmailAddress> < /dev/null
Note: You MUST use the "-r <office365AccountEmailAddress> switch as listed above or it will not work
Disclaimer
This Support Knowledgebase provides a valuable tool for SUSE customers and parties interested in our products and solutions to acquire information, ideas and learn from one another. Materials are provided for informational, personal or non-commercial use within your organization and are presented "AS IS" WITHOUT WARRANTY OF ANY KIND.
- Document ID:7023567
- Creation Date: 06-Dec-2018
- Modified Date:08-Sep-2021
-
- SUSE Linux Enterprise Server
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