Campaign delivery addresses
Below are the addresses you can allowlist if you’re having trouble delivering email from our software to your own network. Depending on your situation, you can allowlist sending domains or IP addresses.
Return-path sending domains
Instead of allowlisting all of our sending IP addresses, you can allowlist our domains. They currently include cmail1.com through to cmail20.com.
If you have set up authentication, you will also want to allowlist the domain you have authenticated. Subdomains can be authenticated, if your mail administrator would like to limit access further.
Sending IP addresses
Below are the IP ranges we use for sending email:
In cases where you need to allowlist IPs to receive email from our servers, we recommend mail administrators set up custom rules within their email filtering software. To work, the rule must match both of these conditions:
- The email is coming from one of our IPs or sending domains (cmail1.com through cmail20.com).
- The email contains your domain in the “From” address.
Any email that doesn’t match one of these conditions can be rejected. A custom rule like this is generally an acceptable solution for security teams and mail administrators.
Upcoming IP addresses
We also own the following block of IP addresses, which will be used in the future to deliver emails.
- ipv6 2404:DE00::/32
Below are the IPs used for webhooks: