FreePBX Voicemail to Email Notification Configuration Using Office 365 - Help!


I was hoping someone could help me out with this. From some of the other posts I’ve gleaned, the setup seems pretty simple, but was hoping to get confirmation.

We have a new FreePBX install and the client uses Office 365 for email. Office 365 is managed by another I.T. firm. We need to set up a Voicemail to Email configuration for our client. From what I understand, with the Office 365 button in FreePBX that’s on our server, we’ll need to do the following:

  1. Add a valid users email/account and password.
  2. Have the Office 365 Admin whitelist the server’s IP.

Here’s a screenshot of the basics. Do I need to use my client’s .com domain, or can I use the defaults in “My Origin” and in “My Domain”?

Any help, tips and tricks would be appreciated. TIA!


Try both…

Anyhow, this seemed to help some users

I recently had an issue where O365 blacklisted my PBX from sending emails. (A big pain in the tuckus… but I digress…)

There are a couple of things that need to happen.

Hostname needs to be a FQDN to your pbx… i.e.
Origin also needs to be the FQDN of your pbx… i.e.
Domain needs to be the top of your domain… i.e.

FINALLY, you need to ssh into the box, and edit:

Look for “myhostname”, uncomment it (if it’s commented) and set it to the fqdn of your pbx…

myhostname =

Next, find smtpd_banner, uncomment, and set it thusly:

smtpd_banner = $myhostname

Finally, restart postfix

sudo postfix reload

Additionally, you’ll need to have a DNS entry for your PBX, an A record is fine, or a CName is fine, that points to the externally facing IP of your system.

So, here’s what’s going on. When you send an email to O365 (Yes, even if you whitelisted the IP), that’s not enough. O365 checks back against the DNS record to make sure that is valid. So the hostname is sent from postfix, and verified against your DNS, otherwise O365 thinks that you’re spamming and just trying to “bounce” email off of their server.

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