No! You cant efile 2019 anymore. Efiling is closed for 2019 and prior. And don't mail another copy. The IRS says NOT to mail again. You just have to wait. If there are 2 or more returns in the system it will delay it even more.
See this IRS page for the latest information
https://www.irs.gov/newsroom/irs-operations-during-covid-19-mission-critical-functions-continue
