Jarkko, there are a number of issues which can affect the performance of WX5, these range from faulty hard disk sectors and fragmentation through to limited disk space, performance is also severely limited if the user chooses to work across a network, via usb or the cloud and if you are unfortunate enough to be in the middle of a large Windows update (I have had recent experience of Win10 update 1709 downloading over 20 times due to failure - this impacted dramatically on pc performance)

Without knowing your setup I recommend exporting the project to create an iwzip, then import the iwzip. This will not overwrite your existing project, it will create a second version. I also recommend running a program like ccleaner (free) to remove all temporary and redundant files lurking on your hard disk.

As for your confirmation email, the details are in settings, shopping cart, sending order tab. You may have sent the confirmation to the database rather than email if you are not receiving it.

If the customer is not receiving confirmation, please ensure that the email address is mandatory when the customer fills in details.

If this does not resolve the issue, I recommend a separate post regarding confirmation emails.