Sophos Email Advanced, while their are many email quarantied as spam their is also email that are 100% spam gets delivered to users.
Did you follow all the process behind Central Email like SPF, DMARC Records etc?
This increase the likelyhood of finding Spam by a lot.
And did you check the Policy, if everything is enabled?
Please make sure that you have followed the recommended settings under the Anti Spam Filtering in Sophos Central." It was noted that email message is analyzed and given a spam score. The higher the score the more likely the message is to be spam.
Messages with the highest spam scores are rated as Spam."https://support.sophos.com/support/s/article/KB-000038822?language=en_US
If it still being delivered even if you have followed the article, I would suggest to get at least one copy of the email and forward to the Sophos Lab for them to confirm if this is a valid to be detected or not. Please follow the kb article below to submit the sample spam directly to Sophos Lab.https://support.sophos.com/support/s/article/KB-000033422?language=en_US
Thanks and have a nice day!
My company email goes to user spam folder, How can I prevent it from going to spam folder. link