Does a mezuza have to contain a parchment handwritten by a scribe, or is a printed scroll also acceptable?
A printed scroll, in this case, is hardly worth the paper it’s written on! A mezuza definitely must be written on specially prepared parchment by a trained scribe. For a fuller answer, see “The Inside Story.”
Is a mezuza effective as an amulet, e.g. in a car or pocket?
No. The mitzva is to place a mezuza on the doorposts of your home. However, the Talmudic Sages noted that a mezuza is distinctive from other mitzvas in its power to protect: Normally a mitzva provides protection while a person is actively engaged in it, whereas the mezuza is a one-time mitzva that provides lasting protection.
What should you do when you pass a mezuza?
According to one opinion, when setting out on an out-of-town journey one should place a hand on the mezuza and say, “Adonoi yishmor tzeisi uvoi” (“May God guard [me upon] my departure and return”). Others have a custom of placing a hand over the mezuza and touching it with their middle finger.
The prevalent custom is to place your fingers on the mezuza and kiss them. Others merely look at it contemplate the words written inside.
What effect does a mezuza have on a person who has one on the doorpost?
As author Moshe Garson writes about wearing a kippa and tzitzit, “Be scientific: try it.” Post a kosher mezuza and contemplate it regularly.
The Sages said, “He who has tefillin on his head and arm, tzitzit on his garment and a mezuza on his doorway is certain not to sin,” because he has many reminders.
In a rented house or apartment, who has to buy and post mezuzas — the tenant or the landlord?
The obligation to post a mezuza falls on the tenant, regardless of whether the landlord is Jewish or not.
Within what time span must you post a mezuza?
If you rent a home outside the Land of Israel or a hotel room in the Land of Israel, you are exempt for 30 days.
If you rent a home in the Land of Israel you must post a mezuza right away.
How often should a mezuza be checked?
Twice every seven years, or whenever a concern arises that the parchment may have been stolen or sustained water damage.
Which doorways require a mezuza?
All doorways of the home. Synagogues are exempt from the mitzva of mezuza because they are not dwelling places. (According to some opinions, a shul where Torah scholars engage in study all day does require a mezuza, since it becomes like a home.)
A doorway to an unclean place (e.g. a bathroom) does not need a mezuza. Likewise a room measuring less than four cubits by four cubits (approx. 2 meters x 2 meters) does not require a mezuza because it is considered too small to be used as a dwelling space. However, a small room that leads to a large room does require a mezuza, and it should be posted on the right doorpost as you enter the larger room.
Does a temporary dwelling need a mezuza?
No. Therefore a succah is exempt from the mitzva of mezuza.