You may want to whitelist an IP address or IP-address range in Exim if your server is experiencing issues receiving messages from that server or from servers in that range. Note that this should only be done if you trust the remote mail servers.
- Go to Home » Service Configuration » Exim Configuration Manager in WHM.
- Select the Edit button next to Trusted SMTP IP addresses.
- Enter the IP address or IP-address range to whitelist in either of these formats:
- A single IP address — Example: 192.0.2.5 or 2001:0db8::0000:0000:0000:0000:0000
- A range of IP addresses — Example: 192.0.2.0/24 or 2001:DB8::/32