Emails from 3CX System to O365

[Evangelion]

Hi all,

We have a few 3CX systems deployed, and we are currently experiencing issues when sending emails (welcome, voicemail, etc) from all the 3CX instances to O365.
Emails from the 3CX instances are able to send to Exchange boxes but not O365.
Affected 3CX instances are all Linux based on the latest software (16.0.910), looked in the logs located at /var/lib/3cxpbx/Instance1/Data/Logs and can't find anything related to failed mail.

Spoke to MS and they have said the emails aren't even hitting their infrastructure.

Any idea what is happening?

TIA

 

[cobaltit]

Nope, but 3CX SMTP works great!

 

[Evangelion]

We are using the 3CX SMTP service.

 

[cobaltit]

Oh sorry, I read that as you were using O365 as your SMTP service. I just sent myself a welcome message and got it, but I have Barracuda in front of my O365. Let me test another email that goes direct to O365.

 

[cobaltit]

Ok tested to O365 (via Barracuda), O365 direct, Outlook.com and G Suite, all good here. I doubt you'd see any error in the logs as your 3CX hands it off to a SMTP server which then passes it on. Since some destinations work and others don't I don't think the initial hand-off is the issue. 3CX uses Sendgrid so there might be a regional issue going on. I'm on the West Coast, US for reference.

 

[JohnS_3CX]

Hi,

Have you tried sending emails using your own SMTP server as a comparison?

 

[ashahrukh]

interesting point