Home / server / Questions / 865012
In Process
Max Allan
Asked: 2017-07-26 01:37:07 +0800 CST

If sendmail fails to resolve smarthost, add to queue rather than fail?

  • 772

Occasionally, in the middle of the night, DNS fails to resolve our smarthost address. And sendmail decides to send the mail as a "rejected" message. Because "root" is aliased to an off-box address, that also tries to use the smart host, and fails. And then I get a savemail panic. Is there any way to persuade sendmail that if it can't resolve the smart host, it can queue the message for later?

I have a horrible feeling I just need to get up at 3am and see wtf is going on with the DNS server :-(

sendmail

1 Answers

  1. Quick fix (temporary?): Use IP address(es) as the smart host.

    define(`SMART_HOST',`[10.0.0.2]:[10.0.0.2]')dnl

    Square brackets turn off looking for MX records.

    Debug procedure suggested:

    1. Use sendmail -d8.20 -bv root to find out DNS queries asked
    2. Make cron execute your test shell script asking the above question every few minutes overnigt
    • 1