Skip to main content

Validation Result Codes

When you validate your email addresses with uSpeedo, we perform a series of deep-level technical checks to determine the quality of each contact. This guide explains what each result field means, helping you decide which emails are safe for your campaigns.

Overview of Validation Fields

Field NameDescriptionPossible Values
SyntaxChecks if the email follows international RFC formatting standards.Valid / Invalid
DNSVerifies if the domain exists and has valid mail server (MX) records.Valid / Invalid
SMTPTests if the mailbox can actually receive email requests.Valid / Invalid
DisposableIdentifies if the email is a temporary, "throwaway" address.True (Disposable) / False (Non-Disposable)
Free EmailIdentifies if the user is using a public provider (like Gmail or Yahoo).True (Free Email) / False (Not Free Email)
GibberishDetects random, bot-like character strings in the email prefix.True (Gibberish) / False (Non-Gibberish)
Catch-allDetects if the server accepts all mail regardless of the mailbox prefix.True (Catch-all identified) / False
SpamChecks the address against global real-time blacklists.True (Yes, Spam) / False (Non-Spam)

Detailed Field Breakdown

1. Syntax

Before we talk to any servers, we check the spelling. This ensures the address isn't missing an @ symbol, has no illegal spaces, and follows the RFC 5322 standards.

2. DNS Check

We verify that the domain (the part after the @) actually exists and is configured to receive mail (MX Records).

Insight: If DNS is Invalid, the company might have gone out of business or the domain has expired. Stop sending to these immediately.

3. SMTP

We ping the recipient's server and test its recipient configuration to see if it's willing to accept a message for that specific user.

Insight: An Invalid SMTP response is a "Hard Bounce" waiting to happen. Sending to these will directly damage your sender reputation.

4. Disposable

Our system uses a massive, frequently updated global database to identify "burnout" addresses (like 10-minute mail).

Insight: Users often use these to grab a "freebie" or discount code without intending to read your future emails. If True, your engagement rates will decline.

5. Free Email

Identifies if the user is using a free personal account (Yahoo, Gmail, Outlook) rather than a custom business domain.

Strategy: If you are a B2B SaaS, you might want to flag Free Email: True addresses to prioritize corporate leads in your sales outreach.

6. Gibberish

We use advanced algorithms to detect if an email looks like it was generated by a human or a random script (e.g., ajksdhf982@domain.com).

Insight: True usually means the address was created by a bot or a user filling out a form with "keyboard mash." These are high-risk for spam complaints.

7. Catch-all

A "Catch-all" server is configured to accept mail for any prefix, even if the user doesn't exist.

The Problem: Because the server says "Yes" to everything, we cannot 100% guarantee the email is valid. This is why Catch-all results are often categorized as Uncertain.

8. Spam

We check if the address or the domain is listed on global anti-spam organization blacklists.

Danger: Sending to a Spam: True address is like walking into a trap. These are often "Spam Traps" designed by providers to catch and block bulk senders. Never send to these.