Postal Service records show delivery delays have persisted across the country as millions of Americans are voting by mail, raising the possibility of ballots being rejected because they arrive too late.

9, the latest numbers available, show nearly all the agency’s delivery regions missing its target of having at least 95% of first-class mail arrive within five days.

That is especially true in states such as Michigan, where ballots must be received by Election Day.

With more than 2.9 million mail-in ballots requested in Pennsylvania, on-time delivery is crucial.

In a statement, Postal Service spokesman David Partenheimer said offices have been authorized to use expanded processing procedures, additional delivery and collection trips, and overtime hours to ensure election mail arrives on time.

“The Postal Service is fully committed and actively working to handle the increase in election mail volume across the country over the next two weeks,” Partenheimer said.

Secretary of State Jocelyn Benson has told voters who have not yet mailed in their ballots to skip the Postal Service altogether and put ballots in a drop box or take them to their local clerk’s office.

Then hundreds of thousands of absentee ballots were delayed when the company printing them became overwhelmed by the volume of ballots requested.

While Ohio allows ballots to be counted if they arrive up to 10 days after the election, they must be postmarked no later than the day before Election Day.