What Philly voters need to know about early voting in the May primary

• Pennsylvania has closed primaries, so only registered party members can vote in their respective elections.

Driving the news: The first batch of mail-in ballots — 73,000 — were sent out to Philly voters on April 23, a spokesperson for the City Commissioner's Office tells Axios.

• Most voters should have begun receiving them this past weekend.

Plus: Mail-ballot drop boxes opened across Philly on Monday.

• These are stationed at more than 30 satellite election offices, recreation centers and firehouses in Philly, as well as the Board of Elections' Office in City Hall.

How it works: Mail-in ballots must be received by 8pm on Election Day.

Worth noting: The deadline to register to vote for the primary is May 4.

• Voters can apply for mail-in ballots through 5pm on May 12.

Zoom in: The most closely watched election in the city is the Democratic primary for District 3.

• The four-candidate primary has split the Democratic Party over the future of a seat held by retiring U.S. Rep. Dwight Evans.

Meanwhile, many of the candidates in the primary are running unopposed, including Gov. Josh Shapiro in the Democrats' gubernatorial primary.