I was building a signup form for a side project. I needed to validate emails. Not just check if there is an @ symbol — actually check if the email can receive mail. Most free validators only check format. That is not enough. Someone can type fake@notarealdomain.xyz and pass a format check easily. So I built MailGuard API. It does real checks. What it does for each email: Checks the format Does a DNS lookup to see if the domain exists Checks MX records to see if the domain can actually receive email Detects disposable/temporary email domains (I have a list of 500+ of them) Detects role-based emails like admin@, info@, support@ — useful if you are building a mailing list Returns a quality score from 0 to 100 Returns a risk level: low, medium, or high There is also a bulk endpoint. You send up to 50 emails in one request and get back a summary with deliverability rate.…