Elections office staffers prepared rigorously for the expected surge in mail-in and drop-off voting this fall: They renewed their training, learned the new rules, got masks and protective gear ready and adjusted their working hours.

But they were not prepared for the thank-you notes.

Tucked into the return envelopes with some ballots were handwritten missives from voters in Fairfax and Loudoun counties: “Thank you for what you do.” “Thanks for making my vote count.” A Halloween sticker or two also appeared.

“It made them feel appreciated, which is great,” said Judy Brown, Loudoun’s voter registrar.

The notes alongside ballots were one of the surprises officials have found in ballot drop boxes, new this year, as loosened rules on mail-in voting in Virginia and fears of coronavirus infections drive hundreds of thousands of voters in the Washington region to cast their ballots before Election Day.

Elections officers have been encouraging voters to review the instructions that come with their ballots and to review the rules for their state or locality because every one is slightly different.

Fairfax County and the D.C. Board of Elections both reminded voters this month to use the provided envelopes before dropping the ballot into a drop box.

“DO NOT deposit a ballot in a Drop Box without an envelope. ALSO, please DO NOT use your own envelope,” the D.C. Board of Elections urged in a tweet.

Elections officials say voters across the region also are showing more anxiety this year over how to properly vote and whether their ballots are being counted. President Trump has raised questions, without evidence, about the security of mail-in ballots and whether the Postal Service will be able to deliver ballots on time. The Postal Service says it can handle the expected volume.

D.C. officials are finding that some voters are returning their ballots without slipping them into the “secrecy sleeve,” the inner envelope intended to keep the ballot secure after the mail envelope is opened, said Nick Jacobs, spokesman for the elections board.

“That’s just fine,” he said. “We’d like you to include the secrecy sleeve, but if it comes without it, we will absolutely count the ballot.”

And tracking ballots has increased the nervousness of some voters, Jacobs said.

“Candidly, there’s a lot of concern when voters see a ballot is under review or it hasn’t arrived — there’s a little lag time because of the volume” of mail-in ballots, he said.

Sealing the outer envelope with tape or “inadvertently using the envelope as a coaster for a cup of hot coffee” will “gum up the works” in processing, but elections officials will still accept the ballot, Jacobs said. But if someone mistakenly votes for three candidates in the city council race in which there are only two open seats, for example, their vote will not count in that race, but the rest of their ballot will count. If there are questions, the elections staff may call voters to straighten out the confusion.

“We’re doing everything possible to allay those concerns,” he said. In-person early voting begins in the District on Tuesday.

In Maryland, where in-person early voting begins Monday, some Montgomery County voters have shown an “overabundance of caution” when submitting their mail-in ballots, said the county’s elections board president, Jim Shalleck.

Some have included pictures or photocopies of their driver’s licenses and other identification. Others have opted to sign every sheet in the ballot package, marking the Spanish language documents even if they filled out the ballot in English.

These efforts are unnecessary, Shalleck said, but do not disqualify the ballots. A small number of voters have signed the ballot itself, which Shalleck said is a “no-no” because the ballot is not supposed to include any identifying information about the person voting.

“With all the publicity and banter over voter fraud, people are doing more than they need to make sure their votes are counted,” Shalleck said, adding that elections officials were surprised by these new trends.

More than 370,000 people applied for mail-in ballots in Montgomery, and about 180,000 have submitted their ballots — although some voters have found it difficult to access the drop boxes, leading the state to issue clarifying guidance on using them.

Fairfax County, Virginia’s largest jurisdiction, has received about 600 ballots — out of more than 144,000 — on which voters forgot to sign the envelopes, Registrar Gary Scott said. “More people seem to be forgetting, sending just the envelope. The ballot is still valid, it just takes a couple minutes longer” to process, he said.

“There’s a fair degree of anxiety out there,” he said, which is evidenced by clogged phone lines to the elections office.

About 400 people in Loudoun County returned their ballots without signing the envelope that has the oath on it, Registrar Brown said. Her staff has contacted all of them, a small fraction of the 46,729 voters who have already turned in ballots, she said.

“People seem happy that we’re reaching out,” she said.

Rebecca Tan, Michael Brice-Saddler and Rachel Chason contributed to this report.