can my employer change me from salaried to hourly with just an email notice?

Under the South Carolina Payment of Wages Act, S.C. Code Ann. 41-10-10 et seq., an employer is required to give written notice seven days in advance of a pay change that results in a decrease in pay, or a pay cut. Your question raises another issue, however. It is likely your employer had misclassified these 14 employees as "exempt" from overtime and paid them a salary regardless of the number of hours they worked. Even though this has been corrected, the employees would be able to recover overtime pay for any hours they worked over 40 per week while they were paid a salary incorrectly at any time over the previous three years. It is important to act quickly due to the statute of limitations in such cases.