3CX SMTP server error

[curbcalamitous]

So our pbx, auto updated on the 14th. and since then it fails to send any form of email. mailbox messages, user registration, password reset, test email. The error I'm getting is that the SSL/TLS cert could not be validated because the CRL was missing for the cert and the intermediate. we're using the 3CX SMTP server. Ive checked the time, the validity of the cert, the connectivity(ports are open), the ip address hasnt changed, I tried rebooting the system. as a temporary fix we've configured it to use our mail relay. but since I have no control over the 3cx server. and I dont know what else to check? we're on the latest version aswell.


It made me pick a system because I'm not logged into our work admin account. but its a self hosted PBX with a license through us as partner. all our other customer PBXs are also unaffected. and theyre also all using the 3CX SMTP server.

 

[KyriacosS_3CX]

Hello,

I would suggest raising a ticket via your Partner Portal so that support can look at this.

 

[curbcalamitous]

yeah since the new update now non of our PBX's can send emails. If i was able to open a ticket, do you really think I'd be here asking questions?

 

[KyriacosS_3CX]

Without more detail - type of system, hosting, versions, fqdn type, etc, it would be difficult to figure out the why.

 

[curbcalamitous]

well then why not just ask for that info?

installation type: local
hosting: Hetzner
FQDN type: not sure what you mean by type. bs-gleichstellung.3cx.berlin
version: Version 20.0 Update 7 (Build 1057 Release)

 

[KyriacosS_3CX]

If you set Verbose loging on, and try a test email, is there something in the logs?

 

[curbcalamitous]

So i turned on verbose logging, then went to send a test email to capture any errors. and suddenly it works again.

 

[KyriacosS_3CX]

I would have to guess that the email or IP was caught in a temporary blacklist somewhere. Do let us know if it happens again so we can investigate further.

 

[curbcalamitous]

Ok so today its not working again, I turned on verbose logging, I see no error messages, under the test I just see 'the server didnt answer: timeout'

 

[KyriacosS_3CX]

Do you have IPv6? Could you disable it and retry?

 

[curbcalamitous]

ok so I can't explain the following behaviour buuuut... I was already at home when i saw you ask about IPv6 and since we do have it I thought I would log in and check since after business hours wouldnt be such an issue.

firstly I couldn't login, even over the VPN so I ended up Remote desktoping into a work server and using it as a jump host. I then logged into 3CX. I went to do an intial test email. It simply sent. then, when I went back to work and tried to send a test email. it failed and now the 3CX SMTP server wasnt responding again. so when I got home from work I did the same thing again, setting it back to 3CX SMTP server over a jump host. and now it works.

 

[KyriacosS_3CX]

I don't have anything very specific to suggest - so far it does look to be network rather than specific PBX settings related.

Within the PBX disable IPv6 though unless you need it explicitly for something. The 3CX SMPP gateway expects to see an IP that matches the FQDN DNS - if the connection is sometimes made via IPv6 or some network bridge, it could be why things sometimes work and sometimes not.

 

[curbcalamitous]

prefer ipv6 is disabled. since i changed it from my home we haven't had any issues, but there were also updates during that time. long as it works and it wasnt a mis configuration in the pbx i can forget about it