Fix Missing Signatures with Mimecast and Xink

When you configured Xink on the Microsoft server-side, and your externally sent (outbound) emails do not get signatures, this is possibly due to Mimecast outbound filtering. These emails are not being rerouted to Xink. Hence, the signature is not applied.

To address this, you need to configure your Mimecast transport rule in your Microsoft 365 to catch emails coming from our relay IP address, depending on which datacenter you are in. See the IP table below.

You need to modify the "Apply this rule" setting as shown below so emails are rerouted to Xink first before Mimecast.