Validating Multi-Instance Postfix

[Ref: OpenBSD 5.4, Postfix 2.11.0 (from ports)]

In general, the process for reviewing, validating the performance of your multi-instance Postfix Server is the same that would be used for a single instance Postfix Server, which we have already referenced in Validating Mail Service

  • connecting to smtp, pop3, imap
  • SSL/TLS Transport
  • Performance
  • Queues


The key issue with the general diagnostics tools, it that it assumes a single running instance and refers to the ‘default’ postfix configuration settings/file.

To let us manage, review multi-instance performance in a consistent command-line sequence, use the postmulti utility in the following manner.

# postmulti -i instance-name -p postfix-command


# postmulti -i instance-name -x shell-command

For example:

To use the postfix command-line options but to a specific instance “instance-name” we would use the following examples:

# postmulti -i instance-name -p stop
# postmulti -i instance-name -p start
# postmulti -i instance-name -p reload
# postmulti -i instance-name -p flush

To use the postfix utilities such as mailq or postqueue we would use the following examples:

# postmulti -i instance-name -x mailq
# postmulti -i instance-name -x postqueue -p
# postmulti -i instance-name -x qshape

All instance reporting

To run postfix commands against all instances, we use postmulti without an instance specification.

The below command, will run mailq for each instance.

# postmulti -x mailq

For cursor style applications such as qshape, I find using the below command incantation a better alternative

# gnuwatch -n 2 postmulti -x qshape