Many banks use Zelle when you want to transfer money to someone at a different bank. There is a scam going around that you need to know about. Basically, it goes like this:
1. You get a text message claiming to be from your bank, asking if you authorized a large cash transfer.
2. When you text back that you did not, you get a phone call from your bank's "Security group". The scammer spoofs the outgoing caller ID so it looks like it's coming from your bank.
3. To "verify your identity" the caller asks you for the email address associated with your account. They then tell you they are sending you a text with a security code, and ask you to read it back to them.
Do not do anything in #3! What the scammer does is initiate a "forgot password" request at your bank's web site which generates the security code. If you give them the email address and security code they can log in as you and drain your bank account.
Remember, your bank will never ask you for your email address, or password, or to read them a security code. That's why you have to set up a "security question" for your account - what was the name of your first pet, that sort of thing. They will use that to verify that it is actually you.
Brian Krebs has a detailed writeup on this.