Unless there was additional consideration offered by you after the modification of the written agreement to establish the payment plan of $500 a month, the monthly payment plan is unenforceable and the written agreement is binding.
The legal relevance of the email would be considered as follows: unless you offered additional consideration for the agreement to accept monthly payments, the agreement to accept monthly payments would be considered a gift and the contractor could retract it at any time.
With respect to the lien, in order for the lien to be placed on the home you and the contractor will have to appear before a judge at which time you would argue that per the written agreement the lien is improper since the work was not yet completed.
Attorney
Negotiate, Draft, and Review many complex commercial agreements each year.
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