Hi! I noticed this problem in my work environment. Clients TB 115.7 64bit (without addons) Os Win 10 22h2 full updated If I open a mail saved in the network or on the desktop and I open it with thunderbird closed it's open fast as I expect, but If I open it with thunderbird already open it is extremely slow, especially on low budget computers, but this behaviour is noticeable also on high end computers. There are some trick that I can do to avoid this? I've tried also to enable/disable the hardware acceleration if avaiable, without notice any improvement. The only way now to avoid this problem is to open the *.eml with another program if thunderbird is open. Thanks