AirLive ES-6000 - Manual (Page 28)

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Reverse DNS lookup:
Reverse DNS lookup determines whether a domain name is associated with the sender’s IP address.
Block Dictionary attacks:
A dictionary attack is an attack which uses a dictionary to randomly generate email addresses that are
directed to the same domain.
Account Request Setting:
ES-6000 allows users performing account registration from the Web Mail login screen. If this feature is
enabled, it is recommended to set the Account Request Setting to Approval by administrator; If set to No
approval needed , then the device might be compromised to send spam.
Max. message queueing time:
What if users’ mails failed the delivery, the mail will save in ES-6000 queue and waiting for the next delivery.
Users can define the lifetime of mail in queue, when the lifetime is end, the mail will be removed from queue
and return a failure notification to sender.
SMTP recipient limit:
The value for SMTP recipient limit will affect the system performance. It is not recommended to set a value
to more than 100.
Enable Local SMTP Authentication:
When SMTP authentication enabled, users must meet one of the requirements listed below to process mail
delivery.
1. Either sender's source IP address or recipient's domain name must exist on the Mail Relay list.
2. Sender has to apply the correct user name and password to SMTP authentication.
Enable Local Delivery Authentication:
Select Enable Local Delivery Authentication function that works to defend mail system against hacker, who
delivers spam mail within the same domain. .
Enable Inbox Quota Auto-Adjustment:
When enabled, the device will:
1. Alert both the user and system administrator about the insufficient space upon inbox usage of 80%.
2. Delete older mails until the usage has lowered to 70% as well as alert both the user and system
administrator about the insufficient space upon inbox usage of 90%. (Figure 4-2)