The technical solution is easy and it is the same solution as when we make bank transactions online: one time pin codes. If another company wants you to send p

The technical solution is easy and it is the same solution as when we make bank transactions online: one time pin codes. If another company wants you to send payments to another bank account, then you mail back the received pin code to that other company via another known email account. If the known email account responds that the pin is legit, then go ahead and change the payment details. Also, before changing the payment details, do send a small amount first, have it confirmed with the other company and then proceed with the test of the payment.