Sophos email filter blocking certain email attachments, unable to allow through

Hello Matt

Good day and thanks for reaching out to Sophos Community

Does the said domain's DMARC and DKIM also outdated? If you suspect all of their DNS checks - DMARC, DKIM, SPF records are outdated or they only use one check which is SPF and could be outdated as well. Could you uncheck setting "Enforce Sender Authentication" on the Inbound Allow/Block and see if email would pass through? 

Many thanks for your time and patience and thank you for choosing Sophos

Cheers,

Hello Matt

Good day and thanks for reaching out to Sophos Community

Does the said domain's DMARC and DKIM also outdated? If you suspect all of their DNS checks - DMARC, DKIM, SPF records are outdated or they only use one check which is SPF and could be outdated as well. Could you uncheck setting "Enforce Sender Authentication" on the Inbound Allow/Block and see if email would pass through? 

Many thanks for your time and patience and thank you for choosing Sophos

Cheers,

Hey Raphael,

Thank you for the response. We were able to update to uncheck the "Enforce Sender Authentication" setting, however, that did not help. We've updated SPF/DMARC/DKIM records on our end to verify that the DNS is not the issue. I've sent an email out to the owner of the domain (Zoho) to seek help, so hopefully they will have some explanation.

Is there any way to check the logs in Sophos for an answer as to why we are getting the Blocked message notification?

Or perhaps, is there a place to alter settings so URLs can be sent in an email besides the Inbound Allow/Block?

Thanks again for your help.

You may try to check report details the messages processed by Sophos Email Security for your protected mailboxes here: https://docs.sophos.com/central/customer/help/en-us/ManageYourProducts/LogsReports/Logs/EmailHistoryReport/index.html

Could you share if you can find any logs referring to said domain, also could you share if there's any NDRs on the end machines.

Thanks for your time and patience and thank you for choosing Sophos

Cheers,