Curved Post

Question:

The historic downtown district of our city has recently been “gentrified,” and we were able to rent a graceful old home quite cheaply. The entrance to the dining room is framed by curved doorposts. If we put the mezuzah on the outer tefach of the curve it will be protruding into the room and won’t be under the lintel. Also, it will be more than a tefach deeper than the opening. Where on the curve can it be placed?

Answer:

To avoid the potential issues you have identified, you should place the mezuzah on the furthest protrusion of the post into the opening and not on the outer tefach. Keep in mind that some authorities assert that one does not need to place mezuzot on the outer tefach of inner doors.^[1]

Placement on other parts of the curve is only acceptable if two conditions are met:

The whole mezuzah should be within the doorframe and not protruding outside.
Even though the mezuzah is on the surface of the post, it should not be deeper than a tefach away from the opening.[2]

[1] Divrei Yetziv Y.D. 191:2.

[2] Agur B’ohalecha 14:3; Mezuzot Beitecha 289:8.