Task: Validate email of new contacts in Hubspot

n8n workflow JSON:
{"id":88,"name":"Check for valid Hubspot contact email","nodes":[{"name":"When contact created","type":"n8n-nodes-base.hubspotTrigger","position":[540,480],"webhookId":"d24ffb14-1e00-4d4e-b3b8-a812690c40d5","parameters":{"eventsUi":{"eventValues":[{}]},"additionalFields":{}},"credentials":{"hubspotDeveloperApi":{"id":"58","name":"Hubspot Developer account"}},"typeVersion":1},{"name":"Get contact email address","type":"n8n-nodes-base.hubspot","position":[720,480],"parameters":{"resource":"contact","contactId":"={{$json[\"contactId\"] ? 151 : 151}}","operation":"get","additionalFields":{"properties":["email"],"propertyMode":"valueOnly"}},"credentials":{"hubspotApi":{"id":"57","name":"Hubspot account"}},"typeVersion":1},{"name":"validate the email","type":"n8n-nodes-base.oneSimpleApi","position":[900,480],"parameters":{"resource":"utility","emailAddress":"={{$json[\"properties\"][\"email\"][\"value\"]}}"},"credentials":{"oneSimpleApi":{"id":"33","name":"One Simple account"}},"typeVersion":1},{"name":"If email is suspicious","type":"n8n-nodes-base.if","notes":"IF\ndeliverability is not good\nOR\nDomain is not valid\nOR\nEmail is Disposable","position":[1080,480],"parameters":{"conditions":{"string":[{"value1":"={{$json[\"deliverability\"]}}","value2":"GOOD","operation":"notEqual"}],"boolean":[{"value1":"={{$json[\"is_domain_valid\"]}}"},{"value1":"={{$json[\"is_email_disposable\"]}}","value2":true}]},"combineOperation":"any"},"typeVersion":1},{"name":"Send to Slack","type":"n8n-nodes-base.slack","position":[1280,460],"parameters":{"text":"=:warning: New Contact with Suspicious Email :warning:\n*Name: * {{$node[\"Item Lists\"].json[\"contact\"][\"fields\"][\"core\"][\"firstname\"][\"normalizedValue\"]}} {{$node[\"Item Lists\"].json[\"contact\"][\"fields\"][\"core\"][\"lastname\"][\"normalizedValue\"]}}\n*Email: * {{$node[\"Item Lists\"].json[\"contact\"][\"fields\"][\"core\"][\"email\"][\"normalizedValue\"]}}\n*Creator: * {{$node[\"Item Lists\"].json[\"contact\"][\"createdByUser\"]}}","channel":"#hubspot-alerts","attachments":[],"otherOptions":{}},"credentials":{"slackApi":{"id":"53","name":"Slack Access Token"}},"typeVersion":1}],"active":false,"settings":{},"connections":{"validate the email":{"main":[[{"node":"If email is suspicious","type":"main","index":0}]]},"When contact created":{"main":[[{"node":"Get contact email address","type":"main","index":0}]]},"If email is suspicious":{"main":[[{"node":"Send to Slack","type":"main","index":0}]]},"Get contact email address":{"main":[[{"node":"validate the email","type":"main","index":0}]]}}}