Trend Email Security allow Voicemail Messages from Microsoft Teams

 Exchange Admin Center in Office 365 to allow voicemail messages from Teams Microsoft. 

Create this rule:

1. Navigate to Exchange Admin Center > Mail Flow > Rules

2. Click on "Create a new rule"

3. Create a new rule that:

Name: Teams Bypass For Trend

Apply this rule if: "The message type is"> include the message type > "Voice Mail"

Sender's IP address is in the range

13.107.64.0/18
52.112.0.0/14
52.120.0.0/14
52.238.119.141/32
52.244.160.207/32
2603:1027::/48
2603:1037::/48
2603:1047::/48
2603:1057::/48
2620:1ec:6::/48
2620:1ec:40::/42 

latest Teams IP addresses - https://docs.microsoft.com/en-us/office365/enterprise/urls-and-ip-address-ranges

4. Do the following...

"Require TLS Encryption"

Then

Chose a mode for this rule: Enforce

Tick

"Stop processing more rule"

5.  Click Save

Move above the ONLY accept Mail from Trend Micro)