Check if IP has blocked with postscreen DNSBL.

• PHP 7 required (tested)
• Move style.css and ajaxsbmt.js in DOCUMENT_ROOT/include dir.
• composer require jbboehr/dnsbl from root rblcheck folder
• Move dnsbl.conf-default in dnsbl.conf.
• Edit dnsbl.conf
  • inserting in [lists] the postscreen_dnsbl_sites, using the same syntax present in main.cf.
  • inserting in [threshold][bl] the postscreen_dnsbl_threshold
  • inserting in [threshold][wl] the postscreen_dnsbl_whitelist_threshold

Are you an Email Administrator, or are you responsible of your own SMTP servers? If you like you can take advantage from this tool also to check if some of your SMTP servers are blocklisted. In this case the postscreen scores are ignored and your IPs are simply checked against list names and values.

• Move mySMTP.conf-default in mySMTP.conf.

  • insert here your SMTP servers IPs.

• Move email.conf-default in email.conf.

  • customize the alert email you receive if some of your SMTP server are blocklisted.

• Schedule computeMySMTP.php

  • You can configure a systemd service/timers as /usr/lib/systemd/system/rblcheck.service:

    ### SMTP Servers RBL Check ###
    #
    
    [Unit]
    Description=RBL check for your IPs
    After=syslog.target network.target
    
    [Service]
    User=root
    ExecStart=/var/www/html/postmaster/rblcheck/computeMySMTP.php
    

    /usr/lib/systemd/system/rblcheck.timer:

    ### SMTP Servers RBL Check ######
    #
    
    [Unit]
    Description=RBL check for your IPs
    After=syslog.target network.target
    
    [Timer]
    OnCalendar=daily
    RandomizedDelaySec = 7200
    
    [Install]
    WantedBy=multi-user.target
    

• See at http(s)://[...]/lookResult.php

Enjoy!