Simple way to filter out most of the disposable / temporary emails

verify-email.ts

import axios from "axios"
import TTLCache from "@isaacs/ttlcache"

const domainsCache = new TTLCache({
  ttl: 1000 * 60 * 60 * 24,
}) as TTLCache<string, Set<string>>

interface ListConfig {
  url: string
  type: "text" | "json"
}

const lists: ListConfig[] = [
  {
    url: "https://deviceandbrowserinfo.com/api/emails/disposable",
    type: "json",
  },
  {
    url: "https://raw.githubusercontent.com/Igloczek/burner-email-providers/master/emails.txt",
    type: "text",
  },
  {
    url: "https://raw.githubusercontent.com/wesbos/burner-email-providers/master/emails.txt",
    type: "text",
  },
  {
    url: "https://raw.githubusercontent.com/7c/fakefilter/main/txt/data.txt",
    type: "text",
  },
  {
    url: "https://raw.githubusercontent.com/unkn0w/disposable-email-domain-list/main/domains.txt",
    type: "text",
  },
  {
    url: "https://raw.githubusercontent.com/disposable/disposable-email-domains/master/domains_strict.txt",
    type: "text",
  },
  {
    url: "https://raw.githubusercontent.com/disposable-email-domains/disposable-email-domains/master/disposable_email_blocklist.conf",
    type: "text",
  },
]

// stuff I want to block, but don't want to put in public lists, because that's paid email providers, just used for spam
const customDomains = ["trungtubemedia.com"]

async function loadDomains() {
  const cached = domainsCache.get("domains")

  if (cached) {
    return cached
  }

  const domains = new Set<string>()

  await Promise.allSettled(
    lists.map(async (list) => {
      const response = await axios.get(list.url)

      if (list.type === "json") {
        // Handle JSON response - assuming it's an array of domains
        const jsonData = Array.isArray(response.data) ? response.data : []
        jsonData.forEach((domain) => {
          if (typeof domain === "string" && domain.trim() !== "") {
            domains.add(domain.trim())
          }
        })
      } else {
        // Handle text response
        response.data.split("\n").forEach((item) => {
          const line = item.trim()

          if (line !== "" && !line.startsWith("#")) {
            domains.add(line)
          }
        })
      }
    }),
  )

  customDomains.forEach((domain) => {
    domains.add(domain)
  })

  domainsCache.set("domains", domains)

  return domains
}

// warm up the cache
await loadDomains()

export async function verifyEmail(email) {
  const domains = await loadDomains()

  const isDisposable = domains.has(email.split("@")[1])

  return !isDisposable
}