Analysis by Barracuda Networks engineers to produce this phenomenon are: e-mail the same host name and mail domain name. In general, the principle is to send the message: the mail server sending mail first to find DNS mx records, mx records if the lookup fails, then the direct use of A records transceiver. This is called the message "delivery rules." Procedures for the different mail delivery rules are different. If you set type = all. Then mail program will be two records, host records and mx records. At a time when many mail programs will be sent directly to the A record. Around the companys e-mail for Fair condition, Barracuda Networks engineers only a small change to solve this problem, change the mail servers host name, such as mail1.xz.gov.cn, so that is not with the e-mail domain with the same name, or domain A record after record on the mx.
In addition, in view of the network in recent years the proliferation of viruses and hacker attacks, especially like "Blaster" Internet worm that attacks the virus, the impact is huge on the network, the firewall on the network, the project is the selection of the operation of Digital China Networks gigabit-class firewall DCFW-1800E-G to achieve the connection INTERNET. DCFW-1800E-G dynamic packet filtering firewall, intrusion detection, traffic management, address translation and other features, can effectively prevent such "shock" that the virus, one can share Internet access, on the one hand for the campus network to achieve higher security.