The SMTP Policy module is responsible for processing policy specifications. SMTP usage-based quota supports message count and message cumulative size over a user-defined period. Message counters can be based on the sender, recipient email address or sender IP address. The main service can be enabled or disabled by clicking the main button Enable/Disable at the top of the page. When disabled all settings will be ignored.
Policies
In the first tab you can define the SMTP policies you will use later. This policies do nothing by themselves, but define the context to which Message Quota and Access Control are applied.
Policies
In the first section are displayed all existing policies. You can filter out the displayed policies by performing a Search operation from the table toolbar.
To create a new policy, you can click on the New button. Each policy is defined by:
- Name
- Description
- Priority
- Status
For each policy you can define multiple rules by expanding the policy record clicking on the arrow on the left of each table record.
To create a new rule, you can click on the New button in the sub-table displayed below the policy. Each rule is defined by:
- Source (the message source such as the source domain or any)
- Destination (the message destination such as the destination domain or any)
- Comment
- Status
Policy groups
Policy Groups can be used to aggregate multiple addresses, domains and IPs into a logical group. Groups can then be freely used in Policy definition, either as source or destination. In this table are displayed all the existent policy group. You can perform a Search to filter out the displayed records.
You can create a new group by clicking on the New button. Each group is defined by:
- Name
- Description
- Status
Each Policy Group is composed by one or more members that define the group matching rules. For example, to create a group of color named domains, I should create one member for each color like (@blue.test, @green.test, @yellow.test etc...). If this group will be associated to a the senders of a policy, the policy will be triggered only by emails coming from email addresses on this group.
Message quotas
In the second tab you can define Message Quotas used to limit the amount of messages or bytes that a client can send over a specific time period, in the context of a matching Policy. A quota is then composed of multiple trackers, which accumulate statistics for message size and count. A tracker can accumulate statistics for each sender, recipient or the whole policy context in a specified time frame. A tracker can then be used to impose limits to the SMTP traffic of the appliance, and proactively block abuse.
You can decide to send a notification to a specific email address by enabling the Notify on quota exceeded option and typing the email address the notification will be sent to.
In the table are displayed all the existing message quotas. You can filter them out by performing a Search.
You can create a new message quota by clicking on the New button from the table toolbar. A message quota is defined by:
- Linked Policy (the policy that defines the context where this quota should be applied)
- Name (the quota name)
- Track Counter (what the module has to monitor for quota reaching)
- Period (how many seconds the module has to apply the verdict to the policy triggering emails)
- Verdict (the action the module has to do when the policy has been triggered)
- Response (the string the module has to send to the client on quota exceeded)
- Stop Processing Rules Here (if more than one rule in chain, this rules will stop the chain)
- Status (enables or disables the quota)
For each quota you can define one or more threshold. You can decide what type of threshold to apply (Message Count or Message Cumulative Size).
Note: current limit values can be verified by clicking on the View Quota icon next to the limit.
Access control
In this last tab you can set the Access Control for each previously created policy. Access Control is used to limit access to the service, either by reject or discarding (silently drop) messages received in the matching Policy context. In the table are displayed all the existing Access Control directives for each policy. You can filter out the records by performing a Search.
Each Access Control directive is defined by:
- Linked Policy (the policy to apply the Access Control directive)
- Name (the Access Control directive name)
- Verdict (the action the module perform when the linked policy has been triggered)
- Status (enable or disable the directive)