Royal Mail bosses have responded to claims post is weeks late and a sorting office has been shut.
Families say their post is weeks late and the Benfleet office, in Church Road, has been forced to close due to a spike in cases.
But Royal Mail says this is not the case and staff are working to provide a normal service as quickly as possible.
A spokesman said: “The office has always been open. I can add that staff absences have been improved and we continue work hard to get back to providing a normal service as quickly as we can.”