"Unfortunately, this is against the terms of the lease and will need to be removed."
The letter told residents that if they did not remove the items themselves, the agents would and "any charge incurred in performing these services will be applied to the offending leaseholder's account".
The letter was shared on Twitter by resident Ivana Bartoletti, who said she was "appalled".
Ms Bartoletti told the JC she had lived in the area for 10 years, adding: "The residents all get on well. I have never heard of a single resident objecting to Mezuzahs."
Philip Glanville, Hackney's elected mayor, said he would raise the matter with Warwick Estates on Monday, calling it "very insensitive and also distressing for the residents involved".
Warwick Estates was not available for comment on Sunday as this story went live.
