Data values in a program are held in variables. Variables are like containers for holding different types of data. A variable can be identified depending on the kind of data it holds. Variables can hold data types of integers, strings, arrays, lists, sets, Boolean etc. They hold unique data types and a can not hold different data types. Different rules exist for naming variables in different programming languages. A variable name should start with lowercase letters and be descriptive of the data it holds.
If you receive in bulk the unsolicited messages, then that does mean that your inbox is being spammed. This will not harm you but you will lose the Gb that is allocated to your mailbox. And if you will not check then your mailbox will soon be full, and you might not receive some of the important messages that you should reply to immediately.