3CX Email Not Being Received

[mikethelad]

I have recently upgraded to Exchange 2019 on premise, all email is working fine apart from emails from 3CX, if on 3CX I specify an external email, it works. I am using the 3CX SMTP Server, so would appear Exchange is blocking this, any ideas? Or would be best to setup an internal relay on exchange and change to a custom SMTP server.

 

[Saqqara]

If you have std license, you have to use 3CX smtp server

For Pro or Ent, I would setup an email relay connector so that the 3CX can send emails thru your exchange server

 

[mikethelad]

Thanks, I have setup an internal relay on Exchange and set 3CX to a Custom SMTP server, and now works, so presume this is the preffered method.

 

[mikethelad]

Test email is working also welcome emails, but voice mail emaiils are not, any ideas?

 

[JohnS_3CX]

Hi Mike,

Do you mean voicemail emails?


These need to be enabled per extension.

Once this is done, you call dial *4+EXT to leave a direct voicemail to an extension and test it.

You should also look at your mail server logs to see the attempt from the 3CX server to send the email, and then if the attempt was made but resulted in no delivery, you will have to troubleshoot from the mailserver end

 

[mikethelad]

I had opened a relay only for the internal IP address off the 3cx / exchange server only, this worked. However after a period of time, the server started sending loads of spam, I have now disabled the relay and this appears to have stopped, the relay is set to allow anonymous logon, is there a better way to do this?

 

[SweetAction]

Is your relay exposed to the internet? If so, why? If not, what malware on your network is even able to talk to the relay?

 

[cobaltit]

This has nothing to do with 3CX, this is an exchange issue. You need to secure your relay

 

[mikethelad]

I have disabled the relay and the email is working as a custom relay for some reason