This petition was rejected

The Government e-Petitions Team gave the following reason:

We understand you're concerned about delivery and courier services, however it's not clear whether you want delivery drivers to be exempt from parking fines or from some other form of 'ticket'.

In any case, parking restrictions are a matter for individual local authorities, not the UK Government or Parliament. You could therefore raise your issue with a local councillor who represents you. You can find out who your local councillors are, and how to contact them, by entering your post code here:
www.gov.uk/find-your-local-councillors

You could also start a petition on the Essex Council website asking them to create some form of exemption from parking requirements for delivery drivers in your area, if that is something you'd like to see happen. You can find out how to do this here: www.essex.gov.uk/get-involved/petitions.