Next year, the mailbox will become the ballot box in one Maryland city.

Late Monday night, the Rockville City Council voted unanimously to move its city elections to a vote-by-mail format — meaning the city’s roughly 40,000 registered voters will receive their official ballots by mail and can return them by mail, beginning with the November 2019 election.

Lois Neuman, chair of the Rockville City Board of Supervisors of Elections, said no other city in Maryland conducts its elections via the U.S. Postal Service. Several states — including Oregon, Washington and Colorado — have adopted a vote-by-mail system.

Neuman said the city opted for the change in the hopes it would increase voter turnout in city elections that of late have attracted barely 15 percent of registered voters. Early voting, which the city instituted in 2015, still didn’t boost the numbers.

“We are still asking the voter to come to the polling place,” Neuman said of early voting. “They need to drive; they need to take time off; they need to bring their children. They still need to come. What about taking the vote to the voter?”

Rockville plans to send out several mailings to voters to inform them of the new election method and make sure addresses on file are still current.

While many details still need to be worked out before the 2019 election, the general process for vote-by-mail elections is in place. The city plans to check the signatures on ballot envelopes it receives by mail against signatures on voter registration forms, to ensure against voter fraud.

It will continue to give voters the option to come to City Hall on Election Day to cast a ballot in the traditional way — using provisional ballots and checking the voting database to safeguard against a voter potentially mailing in a ballot and going to the polls to vote a second time.

“We’re concerned about that too,” Neuman said. “We want to have enough checks and balances so someone only votes once.”

Success, she said, will be measured simply: “Did we get the turnout?” She said city officials are hoping for a modest increase in the numbers.

“If we saw 20 percent, that would be phenomenal,” Neuman said. “That doesn’t sound like much, but for us that would be really good.”

Election law experts say vote-by-mail systems do tend to increase voter turnout.

“What we’ve seen in Oregon and Washington, we’ve seen higher voting rates,” said Eugene Mazo, visiting associate professor of law at the University of Maryland Francis King Carey School of Law and the University of Baltimore School of Law.

One of the advantages of the system is “it allows people a lot more time for deliberation,” he said.

“You have more time to deliberate and think,” Mazo said. “And things like the weather or child care or that you’re traveling that day are no longer an impediment to voting. So what we should see is voting rise. And that’s exactly, empirically, what’s happened.”

And while some have concerns about voter fraud, it largely has not been an issue — especially if the vote-by-mail system is designed well, said Michael Hanmer, a government and politics professor at the University of Maryland at College Park.

“There are more potential risks through an all-mail system than through in-person,” Hanmer said. “But there certainly are trade-offs, and it really does depend on the design of the specific systems.”

Whether the new system will cause delays in getting election night results is still unclear.

“Now we have the go-ahead from the mayor and council; now what we’ll be working on is all the procedures,” Neuman said.

For statewide and federal elections, Rockville voters still will have to show up at a polling place and vote in the usual way.

“We are doing it for the first time. We’ll see how it goes,” Neuman said.