How to configure Mimecast to allow Mailing List emails
Mimecast specializes in email security for Microsoft Exchange and Microsoft Office 365.
Why Emails are Blocked
Mailing Lists are a special challenge for software that is trying to stop spam and malware.
Traditionally, mailing lists keep the original sender of the message in the From: header. However, the email is sent from the mailing list server, not from the original sender's ISP.
Some anti-spam settings will reject emails for this reason.
Mimecast Details
NOTE:
Mimecast is complicated. There are many places within Mimecast to set policies. Two ways to set up a policy allowing mailing list emails are described below.
Option 1
- Navigate to the Gateway / Policies Tab.
- The policy needs to be created in the “Permitted Senders” category, to allow receipt from your bulk mail provider.
- Add Mail-List.com's IP addresses to the "Source IP Ranges" field.
Mail-list.com IP addresses: http://www.mail-list.com/whitelist
See example below to create a new policy:

Option 2
See another example below to create a new policy. This is different way of accomplishing the same result as above.
