How to Fix the 3CX “The IP has been blacklisted”

For the last couple weeks customers have been getting massive amounts of log emails about blacklisted emails.   Of course these are random computers on the internet fraudulently attempting to gain access to your 3CX Phone System.

The good news is that this is very common practice and that 3CX does a good job of identifying and blocking these villains.  These emails can be disconcerting and those attempts can be blocked before they reach your phone system.

Most of our customers have PFSense firewalls installed.  PFSense is an exceptionally well priced enterprise grade firewall and has the ability to properly handle VoIP traffic as well as very advanced security.   To block these fraudulent attempts to access your phone system, I recommend using PFSense and the PFBlocker package.

Stay tuned for a YouTube video on how to set this up.

PFSense firewalls are available from our online store.   We recommend the SG3100 firewall or the SG1000 for very small sites.  Find PFSense firewalls on our online store at:



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Dar Zuch

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