Date: 17 Apr 13:38 GMT/9:38 AM ET US

It has come to our attention that us4-smtp2.titanhq.com / 3.23.0.105 is being intermittently blocked by some Office365 Servers as a "banned sending IP", when it is actually not banned

Recommended actions:

1) Create a Connection Filter in Office365 for our IP address.  This bypasses our IP address from Office365 spam checks (which is advised idea anyway):

https://learn.microsoft.com/en-us/defender-office-365/connection-filter-policies-configure

These are our IP addresses to include:

3.131.225.49

3.147.24.97

3.20.154.217

3.23.0.105

3.136.238.115

2) As per the delist request, it also does no harm to create a support ticket from your recipient tenant (since the delist doesn't think the IP is banned, only some servers.