An unwanted 'explosion' of inbox messages is called

Spamming refers to the practice of flooding the inboxes with an unsolicited emails addressed to hundreds or thousands of recipients in an attempt to force the message on people who would not otherwise choose to receive it. It has also been called "junk e-mail". hope that helps

Explanation:

check the image attached

some main parts enter backspace caps lock shift and ctrl

do not use any of these common illegal characters/symbols:

# pound

% percent

& ampersand

{ left curly bracket

} right curly bracket

\ back slash

< left angle bracket

> right angle bracket

* asterisk

? question mark

/ forward slash

  blank spaces

$ dollar sign

! exclamation point

' single quotes

" double quotes

: colon

@ at sign