Hillary Clinton

Polling prior to the election indicated that those voting by mail favored Hillary.

The vote by mail ballots will be counted if they arrive up to three days after the election. This was all made very clear in the voter pamphlet that was sent out to every registered voter

All other ballots received by 8 P.M on election day WILL BE COUNTED, and provisional ballots are always counted in California elections no matter what the margins.

"Will the unofficial election results change after election night? When will all of the election results be final?
Yes, election results will change throughout the canvass period as vote-by-mail ballots, provisional ballots, and other ballots are processed. Depending on the volume of these types of ballots, it may take up to 30 days (28 days for presidential delegates and 30 days for all other contests) for county elections officials to verify voter records and determine if ballots have been cast by eligible voters. The frequency of updated results will vary based on the size of each county and the process each local elections office uses to tally and report votes.

County elections officials must report their final results to the Secretary of State for presidential delegates by July 5, 2016, and all other offices by July 8, 2016. The Secretary of State will compile the results of the election of presidential delegates by July 9, 2016, and will certify the results of all other offices by July 15, 2016."

http://vote.sos.ca.gov/frequently-asked-questions/#faq-reporting