service postfix restart can't handle postmap executable

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Describe the bug
Running service postfix restart as root leads to following error on shell

/usr/local/opnsense/scripts/OPNsense/Postfix/setup.sh: postmap: not found
/usr/local/opnsense/scripts/OPNsense/Postfix/setup.sh: postmap: not found
/usr/local/opnsense/scripts/OPNsense/Postfix/setup.sh: postmap: not found
/usr/local/opnsense/scripts/OPNsense/Postfix/setup.sh: postmap: not found
/usr/local/opnsense/scripts/OPNsense/Postfix/setup.sh: postmap: not found
/usr/local/opnsense/scripts/OPNsense/Postfix/setup.sh: postmap: not found
/usr/local/opnsense/scripts/OPNsense/Postfix/setup.sh: postmap: not found
/usr/local/opnsense/scripts/OPNsense/Postfix/setup.sh: postmap: not found
Updating aliases
Certificates generated /usr/local/etc/postfix/cert_opn.pem
Certificates generated /usr/local/etc/postfix/ca_opn.pem
postfix: Postfix is using backwards-compatible default settings
postfix: See https://www.postfix.org/COMPATIBILITY_README.html for details
postfix: To disable backwards compatibility use "postconf compatibility_level=3.11" and "postfix reload"
postfix/postfix-script: stopping the Postfix mail system
postfix: Postfix is using backwards-compatible default settings
postfix: See https://www.postfix.org/COMPATIBILITY_README.html for details
postfix: To disable backwards compatibility use "postconf compatibility_level=3.11" and "postfix reload"
/usr/local/sbin/postconf: warning: /usr/local/etc/postfix/main.cf: support for parameter "smtpd_tls_dh1024_param_file" will be removed; instead, do not specify (leave at default)
/usr/local/sbin/postconf: warning: See https://www.postfix.org/DEPRECATION_README.html for details
/usr/local/sbin/postconf: warning: /usr/local/etc/postfix/main.cf: support for parameter "smtpd_tls_dh1024_param_file" will be removed; instead, do not specify (leave at default)
/usr/local/sbin/postconf: warning: See https://www.postfix.org/DEPRECATION_README.html for details
postfix/postfix-script: starting the Postfix mail system

To Reproduce
Steps to reproduce the behavior:

1. Install postfix plugin in stable OPNsense
2. configure it. (I used a smarthost setup)
3. try sending mails: works
4. if you restart the service on cli the reported output is shown

info: the $PATH variable shows following content: /sbin:/bin:/usr/sbin:/usr/bin:/usr/local/sbin:/usr/local/bin:/root/bin

Also a test running the script with custom env does not change anything: env PATH=/sbin:/bin:/usr/sbin:/usr/bin:/usr/local/sbin:/usr/local/bin service postfix restart

However, mails are sent via postfix.

Expected behavior
I assume that a standard service restart doesn't typically result in certain binaries not being found, like Postmap in this case.

Environment
26.7

Start with /usr/local/opnsense/scripts/OPNsense/Postfix/setup.sh and inspect how it invokes postmap during a service restart. Reproduce the issue with service postfix restart in the described OPNsense 26.7 environment, then verify that the restart completes without repeated “postmap: not found” errors and that mail delivery still works.