IP range

General

Name

The name of the IP range. Any text between 1 and 40 characters. Give IP ranges names that describes the ranges, for example My computer, My LAN and so on.

Priority

The priority of the IP range. You can specify a value between 0 and 1000. A higher value means higher priority. If hMailServer matches two IP ranges, the IP range with the highest priority will be used. For example, if a client is matching one IP range with priority 5, and one IP range with priority 10, hMailServer will use the IP range with priority 10. If a client is matching two IP ranges with the same priority, the choice hMailServer will make is undefined.

Lower IP & Upper IP

All IP addresses between (and including) Lower IP and Upper IP will be effected by this IP range. For example, the IP address 127.0.0.4 matches an IP range where the Lower IP is 127.0.0.1 and the Upper IP is 127.0.0.5. The IP address 255.255.255.0 matches an IP range where both the Lower IP and Upper IP is 255.255.255.0.

Allow connections

These settings lets you define which protocols hMailServer will allow, from TCP/IP connections originating from this IP range.

Require authentication for deliveries

These settings defines whether hMailServer should require SMTP authentication for deliveries. For example, if you require SMTP authentication for deliveries to external accounts, the sender must supply a username and password when sending the message. In most cases, you should not require SMTP authentication for deliveries to local accounts.

Allow deliveries

Define whether hMailServer should allow SMTP deliveries for this IP range. Local accounts means accounts on the server. E-mail addresses that does not belong to accounts in your hMailServer installation are treated as external accounts. Note that when sending an email from an alias address, the sender is treated as an external account. You should normally not enable deliveries from external to external accounts for any IP range. Enabling this allows anyone (including spammers) that connects from the IP range to send email through your server.

Anti-spam

If this option is enabled, hMailServer will run spam protection (such as SPF, DNS blacklists and MX check) for SMTP deliveries originating from this IP range. You may want to disable this option for your local network.

Anti-virus

If this option is enabled, hMailServer will run virus protection on deliveries originating from this IP range. You may want to disable this option for your local network.

Forwarding relay

If this option has been selected, hMailServer will assume that any message received from this IP range is being forwarded. Normally hMailServer uses the senders TCP/IP address when doing spam protection. When hMailServer receives an email from a MX backup, hMailServer can't use the senders TCP/IP address since this is the IP address of the backup server. If this option has been selected, hMailServer will try to determine the original senders IP address by parsing the Received headers of the email.

Recommendations

Run open relay tests

After you've changed or added an IP range, you should run at least one open relay test to ensure that no-one can use your server to send spam.

Do not enable external to external

It's recommended that you never enable External to External in any of the IP ranges. If you do, any client which matches the IP range will be able to send email through your server, even if he does not have an account on the server - this includes spammers. For example, if you enable External to External in the Internet IP range, any user on the Internet may be able to send spam through your server. This will typically have the result that your server will become blacklisted by other servers on the Internet, and that legitimate email delivered from your server will be classified by spam. 

It may be safe to enable External to External if it is for an IP range only covering an internal trusted network or localhost. Whether or not it's safe depends on your network set-up and firewall configuration.

Instead of enabling External to External, you should configure all email clients to send from valid accounts on the server.

 

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