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.