Allow Listing of IP Addresses

If you're sending emails to your team members from within an organization, you may face issues because of the same domain being involved. This can be due to the email firewall taking necessary precautionary measures to combat any spoofing attacks, as it deems the same domain receiving multiple emails in quick succession to be a threat.

To educate the email firewall that what you're sending are legitimate emails, you could allow list or whitelist Zoho Campaigns' IP addresses. If you're facing this issue with your contacts, you can request them to whitelist the IP addresses.

What is IP Whitelisting and why is it used?

IP Whitelisting is the process of allowing certain approved, and authentic IP addresses to send and receive emails bypassing the spam filters set by the email firewall.

One of the major uses of IP Whitelisting is in companies. Email firewall has strict security measures to prevent spam and spoofing attacks. Even internal emails from one person to another can get flagged, despite being a legitimate email sent from an authentic IP.

To prevent this, the IP addresses used by the company can be whitelisted. You are essentially telling the email firewall that these IP addresses of your company's email servers are trusted, so there's no need to block emails originating from these addresses.

Advantages of Whitelisting of IP Addresses

Increased email deliverability
Inbox placement
Minimizing emails landing in junk or spam folders
Prevents disruptions within an organization
Improved control over internal email sending

Zoho Account Login URL for various DCs

Your Zoho account can be hosted in different data centers (DC). For example, if you're from Switzerland, there is a chance that your Zoho account is registered in the EU data center. The IP addresses below can change depending on the data center of your Zoho account.

Data Center (DC)	Zoho Account Login URL	Zoho Campaigns URL
US DC 🇺🇸	https://accounts.zoho.com	https://campaigns.zoho.com
EU DC 🇪🇺	https://accounts.zoho.eu	https://campaigns.zoho.eu
AU DC 🇦🇺	https://accounts.zoho.com.au	https://campaigns.zoho.com.au
IN DC 🇮🇳	https://accounts.zoho.in	https://campaigns.zoho.in
JP DC 🇯🇵	https://accounts.zoho.jp	https://campaigns.zoho.jp
CN DC 🇨🇳	https://accounts.zoho.com.cn	https://campaigns.zoho.com.cn
CA DC 🇨🇦	https://accounts.zohocloud.ca	https://campaigns.zohocloud.ca
SA DC 🇸🇦	https://accounts.zoho.sa	https://campaigns.zoho.sa

IP Addresses and Domains to be whitelisted

US DC 🇺🇸

IP Range	Domains
135.84.81.0/24	.Zcsend.net .Zcmail.net
135.84.83.0/24
136.143.160.0/24
165.173.128.0/24
135.84.82.0/24
136.143.161.0/24

EU DC 🇪🇺

IP Range

Domains

91.103.152.0/22

*.eu.zcsend.net

*.zcsend.eu

AU DC 🇦🇺

IP Range	Domains
165.173.160.0/24	.au.zcsend.net .zcsend.net.au
103.138.129.128/27
165.173.191.128/27

IN DC 🇮🇳

IP Range	Domains
103.103.198.0/24	.Zcsend.in .zcinsend.net *.zcmpin.net
169.148.137.0/24
103.103.199.0/24

JP DC 🇯🇵

IP Range	Domains
103.163.153.128/25	*.zcsend.jp
165.173.185.128/25	*.zcsend.jp

CN DC 🇨🇳

IP Range	Domains
124.251.128.4/30	*.zcsend.net.cn
124.251.128.8/29
124.251.128.16/30
163.53.94.0/28
118.126.63.96/28

CA DC 🇨🇦

IP Range	Domains
165.173.164.0/24	*.zcsend.ca
165.173.165.0/24	*.zcsend.ca

SA DC 🇸🇦

IP Range	Domains
199.67.81.192/26	*.zcsend.sa
199.67.83.192/26	*.zcsend.sa

Allow Listing of IP Addresses - Online Help | Zoho Campaigns