With a 4-2, it's much easier to adjust the formation because the setter lines up near the target because they are always a front row player.
Basic strategies for a 4-2 serve receive are...
Pass to the middle
Most beginner teams that run a 4-2 should pass the ball to the middle, then the setter has the option to set the hitters hitting outside and weakside. For a more advanced 4-2 offense, the setter can set out of Right Front. The hitters then have to the option to hit outside, middle, or back.
Train your setters to attack the second hit
Since the setters are always on the front row when setting, they should be given the option to attack. Since you only have two players attacking at the net, the setter dumping or tipping can be an effective strategy.
Have an outlet
If your attackers are forced to receive the serve, or if the pass is so off target that you can't run the play, have an outlet set. Set a back row player to hit a 10 ball or set a ball high outside as an outlet for bad passes.
The following are basic 4-2 rotations. If your team has primary passers, plays a libero, or defensive specialists then adjust your serve receive accordingly.
Volleyball Rotations - Setter in Zone 2The setter is Right Front. The Outside Hitter backs up to help out with passing.
Volleyball Rotations - Setter in Zone 3The Setter is now Middle Front. If needed, the other front row players can back up to help out with passing the serve.
Volleyball Rotations - Setter in Zone 3This is an advanced 4-2 serve receive rotation for when the setter is Middle Front. The front row players are stacked to the left side of the court. The purpose is so the Outside hitter can more easily get positioned outside ready to hit.
Volleyball Rotations - Setter in Zone 4The setter is Left Front. The other front row players are ready to hit middle or weak side.
Volleyball Rotations - Setter in Zone 4Again, this is an advanced 4-2 rotation. The setter is Left Front and the other two front row players are stacked to the left side of the court. Again, the purpose is to run an effective play for the outside and middle hitters.
Remember, these are just examples of 4-2 serve receive rotations. How you line up depends on many factors such as your teams playing level, experience, substitutes coming in for back row players, and using a libero.
All these factors need to be considered when thinking of running a 4-2 offense.