No, the only way to submit the manuscripts to (IJSST) is through the account (login section in Journal's website), and the manuscripts sent to the email will not be considered in the reviewing process.
When the corresponding author registers in the journal system and receives the username and password, he/she could send the manuscript according to the "author guide" available on the journal website.
The number of authors and their names would be in accordance with what is mentioned in the author’s profile. Any request to add or remove anyone or change the order of authors should be submitted before the editorial board’s meeting in a written letter signed by all the authors.