Please add ALL of the delivery IP addresses to your firewall or filters. 


This list was updated and shortened on Jan 1, 2020 with the netblock 204.27.244.0/24


These are the IP's that we use to deliver mail to your servers and having an accurate list configured on your firewall or email filtering tool will ensure that your email arrives at it's the destination. 


INBOUND Delivery Servers

These IP's need to be in your firewall to ensure delivery from our network to your email server. 


Delivery Group 1 - ORE1


104.232.45.0/24

204.27.244.0/24


54.191.214.3

54.149.210.130

54.191.214.36

54.191.151.194

54.148.219.64

54.149.206.185

54.186.27.61

54.191.158.99

54.186.172.23

54.149.36.10


Delivery Group 2 - ORE2


54.149.155.156

54.69.130.42

54.213.22.21

54.200.247.200

54.186.218.12

54.200.129.228

54.149.205.143

54.148.222.11

54.148.30.215

 54.69.62.154


Delivery Group 3 - ORE3


54.68.193.51

54.186.60.165

54.149.154.28

54.148.229.97

54.186.22.84


Delivery Group 4 -  EU1


52.28.30.98

52.29.118.68

52.29.142.239

52.29.144.204

52.29.162.96

52.58.5.29

52.58.7.81

52.58.7.120


End of Inbound Delivery Server IP's


OUTBOUND DELIVERY SERVERS 
These are not required for: 

  • Spam FIltering
  • Phishing Protection
  • Email Forwarding
  • MX Backup
  • Hosted Email
  • Tenant Migration

They are exclusively for outbound email services - https://support.duocircle.com/support/solutions/articles/5000704608-ip-addresses-of-smtp-servers 



The attached file - duocircle_inbound_firewall_ip.txt has the full list of IP's that you can use to import into your firewall. Format text, one IP per line in CIDR notation.