Agudath Israel of America has issued an important announcement regarding the increasing prevalence of what they describe as "problematic" mezuzot in Judaica stores, even in Orthodox areas in mainstream stores.

"We call on sofrim and Judaica stores to remove these problematic mezuzos from our midst," they write, adding, "We call on the public ... to be vigilant and aware of the status of the mezuzos being purchased."

According to Agudath Israel, part of the problem lies with customers who have unreasonable expectations regarding the price of a mezuzah; they also point out that people are ready to spend large sums on their homes and the security systems to protect them, but neglect to take care of their spiritual protection, showing a mistaken set of priorities.

In a short video clip, Rabbi Yisroel Reisman clearly illustrates many of the warning signs in a dubious mezuzah, and one need not be an expert to detect them.

Although missing Tagin (crowns on the letters) do not necessarily invalidate the mezuzah, Rabbi Reisman notes, their absence is often an indication that other problems are also to be found, and he then details them.

On one mezuzah parchment which he displays, the letters on the outside of the rolled-up parchment have been written beautifully by the scribe, but the same letters inside the scroll (only visible if one takes it out of the wrapping to inspect it) are written in a sloppy manner, some in such a way as to invalidate the mezuzah even bedi'eved (in all circumstances).

Agudath Israel also stresses that the yichus (provenance) of the mezuzah is an integral part of its status, as some errors in the scribal process cannot be detected on the parchment and may invalidate it. Thus it is vital to ascertain that the scribe is a G-d-fearing person who is proficient in all the complex laws regarding the writing of mezuzot.