What is the maximum allowed content length of a mail fired through REST API?

What is the maximum allowed content length of a mail fired through REST API?

Hi all,

request example:
{
    "fromAddress": "xxxxxxx",
    "toAddress": "xxxxxxxxx",
    "subject": "EmailAPI - TEST",
    "content": "xxxxxxxxxxxxxxxxxxxxx"
}
My request content size is more than 28 kb. 

zoho response:

[0,{"st":"More than the maximum allowed length"}]
error code: 500


If its possible to send mail via ZOHO API?