Do you check your mail by logging into webmail at http://your-domain/mail?
If you DO, check the Spam Detection box.
If you DO NOT, do not check the Spam Detection box.
—-
That’s the simple answer. The longer answer is that all email that comes to your domain from the outside world goes through a spam filtering process. EVERY SINGLE MESSAGE is marked as spam or not spam.
When you check the “Spam Detection” box, messages marked as spam go into your online Spam folder. The ONLY way to review them is by logging into http://your-domain/mail and then looking within your Spam folder. You can not see these messages any other way. (This makes sense since they are spam and who wants to look at spam?)
The problem is when a messages goes into your spam box that is not really spam. How do you get it out? If you are logged into webmail, it is simple, just transfer it out of the spam box and into another mailbox. However, if you are not logged in… well, there is no way to transfer it out of your spam box.
If you DO NOT get your mail through webmail then Spam Detection is not for you. If you are not getting your mail through webmail, please do not check the Spam Detection box.
—-
Here comes the fun part…
If you have the ability to make mail filters then you don’t need Spam Detection. Create a filter that looks in the email header for the following text:
Yes, hits=
If you find it, the message is spam.