Sophos Email not playing with O365

[jimbopembo]

We've just subscribed to Sophos Email on trial, and I've configured it to filter our O365 traffic Inbound and Outbound. Followed the instructions from Sophos and setup the appropriate (methinks) MX and TXT records on the domain, and setup Connectors in Exchange.

I've just come off a 2 hour call with Sophos Support and I'm losing the will to live! I got the impression that I'm more familiar with the setup than the person looking into it for me. Hoping that I can find some inspiration on here because we are in limbo.

Sophos Support - if you are listening - any chance of speaking to a UK Call Centre?

Specific problem:

Outbound emails no problems.

Inbound emails are registering as delivered successfully in Sophos Central Email Gateway Message History, but don't appear in the Outlook Mailbox. Although emails from fellow domain members work fine.

I've synched with Azure AD and all domain accounts are in Sophos.

Any tips to get this back on the show before anyone notices would be much appreciated.

[kevin_lane]

Are you getting any NDR or any errors

[jimbopembo]

It's all looking good within the Sophos Console. Mail isn't reaching the Outlook mailbox

[willtech]

Can you mail trace in office 365 and does it say it is delivered to the inbox ?

[jimbopembo]

How would I do this Will?

Thx

[jimbopembo]

Got it

[jimbopembo]

only internal emails are viewing in message trace

[willtech]

Is their any emails in quarantine area in the office 365 admin centre ?

[jimbopembo]

It looks normal Will. Just a few that should be there

[willtech]

Ahh ok guessing your mx record in Sophos points to your office 365 mx record as displayed in you domain area of the admin centre. Edited May 26, 2021 by willtech

[chaplic]

O365 as default expects to be receiving mail from the real sender, you have to tell it that there's a third party in the way or it's going to think they are all spoofed if the sender has good SPF rules.

Manage mail flow using a third-party cloud service with Exchange Online | Microsoft Docs

 

 

In Sophos, I assume you have to tell it the explicit dns name to onward deliverto, something like schoolname-sch-uk.mail.protection.outlook.com - is this the right address?

 

It's generally not in the nature of SMTP email to disapear into the ether, it'll either be delivered, bounce, bounce after 48 hours or be caught as spam somewhere.