It depends on the quantity of the marijuana shipped and who arrests you.  California tends to have a lenient approach to the possession or distribution of marijuana-- but it is still a federal offense in California.  If you cross interstate lines and are caught by federal authorities, you could face federal prison time or probation depending on the amount of the marijuana and your criminal history.  The federal system, like many state systems, will increase your punishment for each prior felony on your record.  Smaller prison sentences are around eighteen months.  Longer prison sentences can run around twenty years.  (again depending on your history).  If you have never been convicted of a felony, you would have a good chance at being placed on probation. (The more the marijuana the longer the sentence or the probation.)If you are arrested by a state agency, the analysis would be the same-- but the specifics would depend on the state where you shipped the marijuana to.  However, the punishment could also be affected by the parole laws in the other state.  For example, Texas requires a defendant convicted of shipping marijuana to complete 1/4 of their sentence before being eligible for parole.  This means that on a 20 year sentence, a defendant may only serve five years.  The federal system is less generous with parole-- on the same sentence, a defendant would be required to complete ten to fifteen years before release. Unless you are familiar with the laws of the state where you are shipping the marijuana, you might be better off limiting your activities to California, if that is where you are currently located.