Mimecast Digest Email

As part of its security offerings, Mimecast "holds emails" that it believes are suspicious, are typically considered spam, or are outside your normal email receiving patterns. As Mimecast ingests more of your emails, it will learn more about your habits and the number of false positives of held emails should decrease.

If Mimecast holds a message for you, you will receive an email notifying you. This email, with the subject line "You have new held messages" is sent three times a day (7 AM/0700, 12 PM/1200, and 4 PM/1600, all times EST) which identify messages that are considered spam since the last Digest was sent.

You will have three options for each held message:

You can Block them, removing the message and adding the sender to your personal block list.
You can Release them, which will send the message to your inbox but continue to intercept messages from the same sender.
You can click Permit, which will deliver the email to your inbox AND mark future messages from this sender as safe.

Held messages will be deleted after 14 days if you don’t release them.

For specific information regarding the three different options provided, as well as more FAW, please see this article from Mimecast.