Mail is cracked by brute-force mail gateway How to solve

The company set up a mail server, but has been attacked recently, and two times two accounts have been violently cracked. From the log above, I see constant connection requests for various mailboxes that have received different IPs. Although according to the log put a lot of IP into the blacklist, but still do not rest assured that there is any good way to solve it?

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In fact, for the above situation, there are many e-mails have some precautions.

In the Windows environment

The mail server comes with a similar function of dynamic masking, defining the number of times the connection has failed to block the set time, but this request is actually connected to the server, and the session, the attacker's IP, really how many, this is more difficult to prevent, of course, there are some firewalls, but also to achieve this demand, such as server security dog. However, the process of final connection is always connected to the service and then processed. Greatly increases the load on the server. Waste a certain amount of resources.

The Linux environment

Now generally more commonly used is fail2ban this software, the principle is for the Maillog log error information, and then through the iptables intercept the corresponding peer IP address for a period of time. But after a while, you will see the rules of iptables to turn a few pages can be turned over, to a certain extent, affecting the processing speed. Nor is it a long-term ploy.

Is there a way to deny these malicious connections and directly let a malicious connection fail to connect to the server? See, the current approach, regardless of whether any user can go to the server, whether an attacker or a normal user. will be connected directly to the server and then further processed by the server. This greatly increases the load on the server.

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U-mail How to prevent the Mail security gateway

U-mail e-Mail Security gateway, logic above the isolation of malicious links, the illegal link to shield off. and block out the spam, only keep normal mail delivery to the server, greatly reducing the malicious connection and virus mail caused by the security risks, see below the relevant schematic diagram.

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Can be clearly seen, when the connection through the U-mail mail anti-spam gateway, will undergo a series of scanning purification, and finally only the normal mail sent to the user server, so that users feel at ease to receive mail. Of course, this is just some of the features. It also has a strong ability to handle global mail messaging issues. But this is beyond the scope of this article, just stop here, the specific function, hundred smell than a try, small partners go below to apply for a free trial

Mail is cracked by brute-force mail gateway How to solve