Server sends old messages to new clients

Open Fire 4.7.5 and Miranda-NG client. When installing a new client, all messages that were previously sent to another computer are sent. These are not offline messages, they have already been received. What is this option, how can I disable it? And why are messages saved on the server? How to disable?
This did not happen in earlier versions of 4.0. If you install Pandion as a client, then old messages do not arrive to it.

Without analyzing the XMPP traffic itself, it’s hard to say what is going on. The most probable reason is that the client requests those messages, from a server-sided archive.

What kind of archive is this? Is it possible to turn it off? The server is not required to save messages.

You’re only talking in very generic terms, so I cannot be sure. Does your server have the Monitoring Service plugin enabled? That plugin can be used for message archiving.

Yes, the monitoring plugin is installed. I assumed that it was simply writing messages to the database without sending them out. Then the problem is clear. Thanks for the tip!
The plugin has no settings to prevent sending messages. Apparently we need to look for this in the client. Pandinon and Miranda Im do not collect history from the archive, only Miranda NG somehow receives them. You need to look for the problem in the client.
In general, the option seems to be quite good when the entire history is restored. But in Miranda this is accompanied by hundreds of pop-up windows, so it would be better to turn it off.

It seems that the necessary setting for Miranda has been found:
Network - Jabber - additionally:
Enable archiving of messages on the server (XEP-0313) - disable

If you need the message archive to be restored on a new client:
Enable history on the server (XEP-0136) - enable
This setting will allow you to receive message history when you open a contact. A lot of messages may drop out, but this is better than messages from all users dropping out when connected. In addition, the correct datetime of the message will be shown.
But if the user clears the history on the client and then reinstalls the client, this setting will restore the cleared history back.