I'm a bit stumped been working on trying to fix this issue for a few days now and decided it's finally time for help.

Essentially, I setup a new Ubuntu 16.04LTS server used to host my Joomla intranet site. It's running PHP7.0, Apache2, Postfix (For sending emails only), MySQL Server, pretty much the whole lamp stack. I have an internal exchange server which I inherited as I just started this job about two weeks ago and was provided no info on the servers.

I'm trying to get Joomla and by extension the ubuntu server to talk to the exchange 2016 server for email relay. When using Joomla's SMTP function and plugin the details, it fails to find the SMTP host. To test this I connected Joomla to my gmail account via the SMTP option and it was successful. The PHPMail function says it sends the email, but there's no email in the inbox.

I've already added the correct domain name and relay host in the postfix main.cf but I've got no luck. Any help would be appreciated.

1 Answer 1


I found the resolution. It turns out my inherited exchange server was configured incorrectly. For those of you who may experience the same issue, here's what I did to fix it in exchange 2016.

In exchange, select Mail Flow > Receive Connectors and create a new one.

For this instance, instead of allowing all sources to send to the exchange server, you will only allow the selected linux/ubuntu server.

  1. Provide the new receive connector a name
  2. Verify Server address
  3. Select Frontend Transport
  4. Select the type: "Internal"
  5. Remove the default IP Address range and only include the source server IP
  6. Hit Finish
  7. Open the newly created receive connector and select security, ensure the following are checked:
    • Transport Layer Security (TLS)
    • Exchange Server Authentication
    • Exchange Servers Only
    • Legacy Exchange Servers
    • Anonymous Users
  8. Select Scoping
  9. In the "Network adapter bindings" leave the IP Addresses to "(All Available IPv4)"
  10. Change Port to 587 or desired port
  11. Click Save

That's pretty much it. It was driving me up a wall bc it just wouldn't work and to be honest I'm new to exchange server. I just wanted to post a resolution because I could not seem to find any info on how to really resolve this across the web. So hopefully this solution will come in handy for those who may face the same issue. Learning as I go, but aren't we all.

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