How to stop Outlook 2010 from trimming incoming emails (html)?

Question

System administration

The essence of the problem is the following. The network uses two mail clients: Outlook 2010 and Web interface (browser). When sending messages from a browser (message format html) to a client who works through Outlook, all correspondence disappears completely, only the last message remains.
In the vastness of the worldwide web, I found a solution that helps somehow partially, i.e. once at a time it doesn’t have to - either it cuts, or it doesn’t. The essence of the solution is to add the following content to the registry to change the encoding to Base64
[HKEY_CURRENT_USER\Software\Microsoft\Office\14.0\Outlook\Options\Mail]
"InternetMailTextEncoding"=dword:00000002
In general, the problem is still relevant and haunting .

Answer 1

did not understand, you need to disable Outlook trim or when forwarding from the browser (OWA)?

Answer 2

Ivanov received a message from Sidorov - "I'm fine." Then Ivanov forwarded this message to Petrov and added "I, like Sidorov, everything is fine." When Petrov opened the message, he saw only Ivanov's text "I, like Sidorov, everything is fine," without the text from Sidorov's message.
Petrov's mail client (Outlook) truncated the message sent from the Web interface of Ivanov's mail.