Hello, after upgrading to v9.9, build 6397 lots of emails are being treated as spam.

Even if they are whitelisted

Kevin,

Please refer to https://www.xeams.com/whitelisted-addresses-ignored.htm for an explanation and how to configure Xeams to bypass this rule.

I have read the article. 

There section which goes on to show how to skip DMARC globally refers to a server.properties file, I don't seem to have this file?

Kevin,

Please create it. Refer to https://www.xeams.com/server-properties.htm for more information.

I created the file as advised. Followed the instructions, however, emails are still being blocked? What next?

What is the exact build number that you're using? If it is less than 6398, update it manually following instructions on https://www.xeams.com/manuallypatching.htm.

Additionally, go to Tools > About and search for ignore.dmarc.alignment.in.sender.filter. If you don't see it on the page, that means Xeams is unable to read the server.properties file.

The file server.properties is in the config folder and has the same properties (owners etc.) as other files in that directory. It contains the one parameter ignore.dmarc.alignment.in.send.filter=true howver it does not appear in the Tools > About page!

I have updated the version manually

If you don't see the property in the About Screen, that means Xeams cannot read the file. Are you using Xeams on Windows? If yes, ensure the file extensions are not hidden in Windows Explorer. Hidden extensions often cause users to create a file like server.properties.txt, and they never realize the mistake because the name appears correctly when viewed in the Explorer.