How to reduce the amount of RAM used in Thunderbird?

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Good afternoon.
Help, please, to solve a problem.
Faced with the fact that the Thunderbird mail client takes up a lot of RAM (in the screenshot)

The ExQuilla for Microsoft Exchange add-on is installed.
The size of the box is quite large 20 gigabytes.
Global indexing is disabled.
Who knows what could be the problem and how to solve it?
Perhaps it's possible to limit memory consumption by Thunderbird itself?
Thank you.
Sincerely, Dmitry.