It is observed that the notifications that are sent as the SPAM Digest Email are received in the next business day. These notifications are very important and they should be received in real-time without any delay, in order to ensure a timely response.
Regarding the Spam Digest, unfortunately, there is no option to send this notification in real-time, there are only options to set a specific frequency Daily, Weekly, or Monthly at one specific hour:
An alternate option that may be more efficient to notify the user about Spam that has been quarantined and that is the Quarantine Digests. This can be configured to send the digest as often as you need, by adding extra rules: