California allows precincts with fewer than 250 people the option to conduct elections by mail only.
Voters in other precincts have the option to request mail ballots for a single election or for every election. An August report by the California Voter Foundation found that in Sacramento County during the 2012 November election, ballots from all-mail precincts were more likely to be rejected than other mail ballots:
Notably, Sacramento County provides postage-paid return envelopes only for voters in all-mail precincts. The business-reply unit of the U.S. Postal Service, which processes postage-paid ballots, experienced greater delays than the units that process first-class mail, a factor that may account for the inconsistencies in rejection rates.
Among ballots mailed first-class, some have insufficient postage. These are still processed by the Postal Service and delivered to the elections office for counting. Sacramento County covers this expense at a cost of $500 or less during statewide elections.
In February, we wrote about another report, which found that in 2012, 47 percent of California’s uncounted mail ballots were rejected because they arrived after Election Day.