messageBody

The message to send. The minimum size is one character. The maximum size is 256 KiB.

A message can include only XML, JSON, and unformatted text. The following Unicode characters are allowed:

#x9 | #xA | #xD | #x20 to #xD7FF | #xE000 to #xFFFD | #x10000 to #x10FFFF

Any characters not included in this list will be rejected. For more information, see the W3C specification for characters.