Setting incoming mail restrictions

Setting a maximum incoming message size


    You can enable or disable a message size limit and specify the maximum size of an incoming message.

  To set a maximum incoming message size, follow these steps:
1 Open the Mail Admin program, if it's not already open.
2 If the Mail Server is not already running, choose Start Mail Server from the Server menu.
The Mail Server starts up.
3 Choose Mail Server Settings from the Server menu.
The Mail Server Settings window appears, and shows the General mail settings.
4 Click the Mail In tab.
The Mail In settings appear.
5 To enable the maxium message size limit, click the "Message Size" checkbox so that a checkmark appears. Then type a number for the maximum message size in the text box.
When this box is checked, users will only be able to receive messages up to the indicated message size. Messages larger than this size are sent back to the sender.
To disable the maxium message size limit, click the "Message Size" checkbox so that the checkmark disappears. When this feature is disabled, users can receive messages of any size.
6 Click Save.
Your changes are saved and take effect immediately.


Accepting mail only from known users


    You can refuse incoming mail from users or groups who are not in the local Users & Groups List, or from domains that are not in the Host list. You may want to do this if your server is receiving a high volume of unsolicited mail (or "spam"), or to prevent individuals from creating invalid "from" addresses.

    For example, if someone sends mail to "traviswayne@company.com," where the domain "company.com" is a valid domain name for your Mail Server server but the "traviswayne" doesn't exist in your Users & Groups List, the Mail Server would reject the message because the "from" address doesn't have a corresponding entry in the Users & Groups List.

    An invalid "from" address is one that includes a user who is not in the local users and groups list, a user for whom mail is disabled, or a domain that is not included in the defined Host list. To learn more about the host list, see Editing host-specific settings.

  To refuse mail that has an invalid "from" address, follow these steps:
1 Open the Mail Admin program, if it's not already open.
2 If the Mail Server is not already running, choose Start Mail Server from the Server menu.
The Mail Server starts up.
3 Choose Mail Server Settings from the Server menu.
The Mail Server Settings window appears, and shows the General mail settings.
4 Click the Mail In tab.
The Mail In settings appear.
5 Click the "Require local ‘From' addresses to exist in User & Groups" checkbox (near the bottom of the window) so that a checkmark appears.
When this box is checked, any mail with a "from" address that matches your Mail Server's local domain names is verified and accepted. Mail with a "from" address that does not include a name in your Users & Groups List is sent back to the sender.
To disable this restriction, click the "Require local 'From' addresses to exist in Users & Groups" checkbox so that the checkmark disappears. When this feature is disabled, messages from any user or group can be sent users on your server.
6 Click Save.
Your changes are saved, and take effect immediately.


Rejecting mail whose host is not in the host list


    You can reject mail that is sent from or to a host (or "domain") that is not listed in the Host List. The Host List is automatically created by the Mail Server, and includes each mail server domain to which mail has been sent or from which mail has been received. You might want to restrict users to specific host settings if you need greater control over mail activity.

    Note: To view the Host List, choose Show Host List from the Mail Admin program's Server menu. For instructions on limiting the Hosts that can send or receive mail, see Editing host-specific mail settings.

  To reject mail sent from hosts not in the host list, follow these steps:
1 Open the Mail Admin program, if it's not already open.
2 If the Mail Server is not already running, choose Start Mail Server from the Server menu.
The Mail Server starts up.
3 Choose Mail Server Settings from the Server menu.
The Mail Server Settings window appears, and shows the General mail settings.
4 Click the Mail In tab.
The Mail In settings appear.
5 Click the "Reject mail if host is not in host list" checkbox (near the bottom of the window) so that a checkmark appears.
When this box is checked, the Mail Server only accepts mail being sent to or from a domain listed in the Host List. Mail sent to or from other domains is returned to the sender.
To disable this restriction, click the "Reject mail if host does not exist in Outgoing mail" checkbox so that the checkmark disappears. When this box is not checked, the Mail Server accepts mail being sent to or from any mail server host.
6 Click Save.
Your changes are saved, and take effect immediately.
Note: If you enabled the mail restriction, any future incoming mail with invalid domains will be sent back to the sender. Recipients can still connect to the Mail Server to retrieve any mail that was stored in the mail database before this restriction was enabled.

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