A way of saying yes, usually used when one acquiesces or consents to a plan, decision, or request about which one is generally ambivalent. Typically read as "Whatever"
"Hey do you want to go grab lunch with me?" *excitedly*
"Sure thing" *flatly*
邮件由 firstname.lastname@example.org 发出。我们决不会发送垃圾邮件。