I’m unhappy with my current validator missing disposable emails

If your validator is missing disposable emails, the likely fix is to add a reliable disposable-domain check in addition to syntax and MX checks.

What to do

1. Keep basic email validation

   • Syntax: name@domain.com
   • Domain/MX lookup if you already do deliverability checks

2. Add a disposable email blocklist

   • Check the domain against a maintained list of known temporary email providers
   • Include subdomain handling, e.g. mailinator.com, *.mailinator.com

3. Use an external data source

   • Options:
     • A curated disposable-domain list in your codebase
     • A third-party API/service
     • Periodic sync from a public blocklist repo

4. Normalize before checking

   • Lowercase the domain
   • Trim spaces
   • Extract the registered domain correctly using the Public Suffix List if you want to avoid false negatives like something.co.uk

Good validation flow

• Parse email
• Validate format
• Extract domain
• Check disposable domain list
• Optionally check MX records
• Optionally check SMTP/verification service

Caveats

• Disposable providers change often, so a static list goes stale quickly
• Some legitimate domains may host temporary inbox services, so expect occasional false positives
• If you want higher accuracy, combine:
  • disposable-domain list
  • domain reputation score
  • MX/DNS checks

Example logic

if not valid_email_syntax(email):
    reject

domain = extract_domain(email).lower()

if domain in disposable_domains or parent_domain(domain) in disposable_domains:
    reject

accept

If you want, I can help you with:

• a disposable-domain list strategy,
• a code example in your language,
• or reviewing your current validator to see why it’s missing these addresses.