Solved Sending Welcome emails and Voicemail to email stopped working for external users with Different domain

[dza]

Hi All,

I have two different groups of users on my 3cx system:

Group one with @ABC.com email domain

Group two with @EFG.com email domain

I have been using the same custom SMTP server for years now without any issues, sending welcome emails and voicemail to email to both different email groups. The Reply address in my 3cx Email settings is a shared office mailbox with the @ABC.com domain that doesn't require authentication. It has been configured using Option 2, as listed in this article (How to set up a multifunction device or application to send email using Microsoft 365 or Office 365 | Microsoft Learn). I can confirm that my email settings are correct because the SMTP test is successfully completed, and I have no issues sending welcome emails and voicemail to email to the users who are part of the same domain as my shared mailbox domain.

However, recently, sending welcome emails and voicemail to email has stopped working for users who are using a different email domain than @ABC.com. I haven't made any configuration changes in our Office 365 or 3cx system. I tried to run a message trace on both mail tenants, but there are no traces of these undelivered messages. Has something changed with the latest update that I'm not aware of? I am currently running version 18.0.7.312.

Also, what's the best way to troubleshoot this issue using the 3cx logs?

Thank you for your assistance.

 

[Alejandro_3CX]

Hi @dza I wonder if using the 3CX SMTP do you have the same the issue or not?

 

[dza]

No acutally I don't have the same issue when using 3CX SMTP server.

 

[Alejandro_3CX]

So, in this scenario you will have to check it on the custom SMTP used and start debugging from there.

You may check also the systemservice.log for further information (with the logs in verbose mode) and start a packet capture so you can check the traffic sent to the smtp.

You will see a log entry for example

2023/07/24 18:30:07.351|30919|0040|Info|[_3cxSystemService.ExtSheduller.WelcomeEmailSender] Enqueued sending welcome email to 301

2023/07/24 18:30:07.425|30919|0040|Info|[_3cxSystemService.ExtSheduller.WelcomeEmailSender] Sending welcome email to extension 301

This means the system sent the welcome email, then if the system got any error you may see it in this log.

Hope this helps you troubleshoot your issue.

 

[VoIPTools]

Your SMTP server is not allowing 3CX to "relay" emails outside your domain. This is not an issue with 3CX, it is an issue with the account you are using to authenticate to your SMTP server and what rights this user has on the SMTP server.

You will need to talk to the people managing your mail server. I would not be surprised if you get pushback from your technical staff who will "say" they have relay configured correctly. Nevertheless, the fact is that you have already done the diagnosis.

If 3CX can send emails internally, but not externally, this proves that 3CX can send emails. 3CX does not care whether it is an in-domain address or outside-domain address. It just sends emails and the mail server applies restrictions. I promise you, 100% of the time (and I have delt with this issue a 1000+ times over the years) it is ALWAYS an SMTP issue, not a 3CX issue.

 

[dza]

Issue resolved.

1. I collected and inspected the 3cx log using Wireshark

2. The log showed the Rely access was denied

3. I noticed my Office 365 connector was still using my old static IP address ( My Static IP changed a month ago)

4. I updated the IP address on the connector and the issue was resolved.

Thanks for the tips to help me troubleshoot this issue. I really do appreciate it. This community is awesome.

 

[Alejandro_3CX]

glad to hear it is working now, have a great week ahead!