Many web sites ask users to enter their email address twice, sometimes taking the trouble to disable copy-pasting.
What is the logic behind this? Is this e.g. a security measure?
I suspect a lot of it is "Grandma's Cooking Secret" programming where the programmer does it because they saw someone else do it. It's following tradition without thinking.
There could some logic originally behind it, such as users in 1996 not knowing that much about how to format email addresses. It could have been done then to avoid errors but then why not double every visible field? However, it probably isn't needed today and is an extra pain for mobile users.
Now, disabling copy/pasting and other tricks can be useful to prevent some automated spamming but they should be non-intrusive for the most part to normal users.
It's just to try and ensure that you enter the correct address, without typos. Since email addresses are usually the primary contact information for websites, it's considered worth the extra effort to try and make sure it gets entered correctly.
It's sometimes called two-pass verification.
It is just the old way of confirming the email address. In old days, you had to enter the same email twice in order to verify it, in the new way, you have to click on a link inside the email to verify it. The new way is far better and makes the first one obsolete.
In this particular case, there is an extra emphasis on email just because it is money related site which is obvious. Other than that this method is not prevalent these days.
Short Answer: It is done to prevent the typo (mistakenly entering email address) !
Without this check, user may enter a wrong email address and never get registration feedback email, because he has entered wrong email address. In addition, this checking measure is
prevent mass spamming by CaptCHA implementation in place.