3CX SMTP Server - 5.7.0 Denied Error Message

[Benjamin Williams]

I can see within my logs that I have a considerable number of errors related to the 3CX SMTP services. (see below).

If I test the SMTP server, I get a 5.7.0 Denied Error Message... However, it's very intermittent, after I click on the 'Test' button a few times, the email will eventually go through and successfully received.



Here is the event log...




This just started happening today.

I upgraded to Release 2 and the problem persists.

 

[TheodorosG_3CX]

Are you using a Dynamic Public ip?

 

[Benjamin Williams]

No, we are using a static IP from our CIDR block.

 

[NikolasA_3CX]

This error is usually shown when the FQDN IP and the External IP are not the same.
Can you please check and confirm if this is the case?

 

[Benjamin Williams]

This error is usually shown when the FQDN IP and the External IP are not the same.
Can you please check and confirm if this is the case?

They are both the same... I can perform an NSLOOKUP using a variety of external DNS servers and they all resolve to the same WAN IP address that we are using on our PBX.

The SMTP server works about 25% of the time, the other 75% is fails and results in email notifications not being delivered to the intended recipient(s).

My PBX instance is configured with two internal DNS IP addresses (e.g. both our primary and backup domain controllers). I am wondering if I should configure a public DNS server on the PBX?

 

[NikolasA_3CX]

Yes try using a public DNS and check again.