Just checked the admissions page and it says " Beginning Tuesday, January 7, the Admissions Office will only be available by phone from 1 p.m. to 4 p.m. EST in order to process and review applications more efficiently. If you have questions about the online application or are experiencing technical difficulties, please visit our Technical Support page for answers to commonly asked questions." (https://www.gse.harvard.edu/admissions/apply)
I don't know if it applies to emails, but the university is also closed on Monday. I hope you hear from admissions in the next half an hour if you decide to write to them/ I hope we all hear some good news soon.