IP protection restricts which IP addresses can send emails through your Direct Mail account via SMTP and API calls. By maintaining an IP address whitelist, you prevent unauthorized sources from sending emails on your behalf.
IP protection applies only to emails sent using SMTP or API calls. Emails sent directly from the Direct Mail console are not affected.
Prerequisites
The public IP addresses of all servers and applications that send emails through SMTP or API calls. You need to add these addresses to the whitelist before you enable the feature.
Before you begin
Add all of your sending IP addresses to the IP address whitelist before you select the Enable IP Whitelist checkbox. After you enable IP protection, emails sent from IP addresses that are not in the whitelist are blocked.
If your sending IP address changes after you enable IP protection, update the IP address whitelist immediately. Otherwise, your emails will fail to send.
Procedure
Log on to the Direct Mail console.
In the left-side navigation pane, choose Email Settings > IP Whitelist.
Add the IP addresses, IP ranges, or CIDR blocks that your servers use for sending emails to the IP address whitelist. Enter one entry per line. For supported formats, see IP address formats.
Select the Enable IP Whitelist checkbox.
Add your IP addresses (step 3) before you select the checkbox (step 4) to avoid interrupting your email traffic.
IP address formats
The IP address whitelist supports three formats. Enter one entry per line.
| Format | Syntax | Example |
|---|---|---|
| Single IP address | xxx.xxx.xxx.xxx | 220.181.12.241 |
| IP range | xxx.xxx.xxx.xxx-xxx.xxx.xxx.xxx | 220.181.12.241-220.181.12.255 |
| CIDR block | xxx.xxx.xxx.xxx/N | 220.181.12.0/24 |
A CIDR block uses a prefix length (/N) to define a range of IP addresses. For example, 220.181.12.0/24 covers all 256 addresses from 220.181.12.0 to 220.181.12.255.
Do not enter private network IP addresses. The following private IP ranges are not supported:
192.168.0.0 - 192.168.255.255
172.16.0.0 - 172.31.255.255
10.0.0.0 - 10.255.255.255
Limits
| Item | Limit |
|---|---|
| Maximum whitelist entries | 10 |
| Entries per line | 1 |
| Private IP addresses | Not supported |
| Scope | SMTP and API calls only (console sending is not affected) |
What happens after you enable IP protection
After you enable IP protection:
Whitelisted IP addresses: Emails sent from IP addresses in the whitelist are delivered normally through SMTP and API calls.
Non-whitelisted IP addresses: Emails sent from IP addresses that are not in the whitelist are blocked.
Console sending: Emails sent from the Direct Mail console are not affected by IP protection.
To maintain uninterrupted email delivery, update the IP address whitelist immediately when your sending IP address changes.
FAQ
Q: What happens if I enable IP protection without adding any IP addresses?
A: All emails sent through SMTP and API calls are blocked because no sending IP address matches the empty whitelist. Emails sent from the Direct Mail console are not affected.
Q: Does IP protection affect emails I send from the Direct Mail console?
A: No. IP protection applies only to emails sent using SMTP or API calls. Console-based sending is not restricted.
Q: Can I add private network IP addresses to the whitelist?
A: No. Private network IP addresses (such as 192.168.x.x, 172.16.x.x - 172.31.x.x, and 10.x.x.x) are not supported. Use public IP addresses only.
Q: My sending IP address changed and my emails stopped working. What should I do?
A: Add your new sending IP address to the IP address whitelist. Emails from IP addresses not in the whitelist are blocked when IP protection is enabled.
Q: How many entries can I add to the IP address whitelist?
A: The whitelist supports a maximum of 10 entries. Each entry can be a single IP address, an IP range, or a CIDR block.