IBM Support

How to Configure Sendmail not to Look up MX records.

Troubleshooting


Problem

A default sendmail configuration will do DNS queries for MX records, it does this even when its setup to use a Mail Relay Server for sending mail out. This will cause mail to fail if its not able to lookup the MX record.

Resolving The Problem

Setting up sendmail not to query DNS for MX records when using a DS (Smart Relay) consists of using "[ ]" brackets around the hostname Mail Relay Server configured in the /etc/mail/sendmail.cf.

#vi /etc/mail/sendmail.cf

Search for DS

Example:

DSnetmail.austin.ibm.com

change to:

DS[netmail.austin.ibm.com]

Save the configuration file...

refresh -s sendmail

[{"Product":{"code":"SWG10","label":"AIX"},"Business Unit":{"code":"BU058","label":"IBM Infrastructure w\/TPS"},"Component":"Not Applicable","Platform":[{"code":"PF002","label":"AIX"}],"Version":"5.2;5.3;6.1","Edition":"","Line of Business":{"code":"LOB08","label":"Cognitive Systems"}}]

Document Information

Modified date:
19 August 2022

UID

isg3T1011217