Is an email from an employer, confirming a condition of a contract with the employee, legally binding?

It depends on numerous differing facts.  You should speak with a local attorney to determine if the email would constitute an amendment to the original contract. This is not intended to be legal advice, and is general in its nature. No attorney-client relationship exists or is formed by this information. Furthermore, this does not represent the views or opinions of LexisNexis or its affiliated companies.