Zimbra Forums

Good afternoon everyone.
My name is Carlos.
It's my first thread in the forum. I have the following problem

I installed the version of zimbra 8.7.11_GA-1854.FOSS.
I have installed two servers. One in LAN area and the other in DMZ zone. The server in the LAN zone has the ldap, mailbox and logger roles as the main ones. The DMZ server has the functions of proxy, mta, antivirus, antispam, memcached.

When I access the internal server by browser, I sometimes write the emails and send them normally. But sometimes it stays hanging with the windows icon going around and says that the server or network is slow and then sends the message.

With the zimbra desktop client it does not give the same problem. It only happens via browser.

I would appreciate any help on the subject.

Welcome to the forum.

Have a look at this: https://wiki.zimbra.com/wiki/DoSFilter

Dear,

Some spammers/dos attackers try to establish multiple smtp connections to your mta and do not release those connections. Your RAM and CPU usage is low but smtp handler is overload and does not accept new good smtp submission connections. You can use Postscreen to filter off those bad connections.
You can list how many smtp connections by: Focus on IP which has a lot of smtp connection.

Regards,
Minh.