Validation Strategies

Truelist offers four validation strategies to meet different needs. Each strategy balances speed and accuracy differently, allowing you to choose the best approach for your use case.

Fast

The Fast strategy performs a quick validation of email addresses. It prioritizes speed over thoroughness by:

• Not retrying failed SMTP connections
• Skipping deep validation checks
• Returning results as quickly as possible

Best for: Scenarios where speed is more important than accuracy, such as real-time validation during form submission or when processing very large lists quickly.

Accurate

The Accurate strategy is the default validation method. It performs a thorough validation of email addresses, including:

• Retrying failed SMTP connections to reduce false negatives
• Performing deep validation checks
• Balancing speed with reliability

Best for: Most scenarios. This strategy provides a good balance between validation thoroughness and processing time.

Thorough

The Thorough strategy extends the Accurate strategy with additional patience for servers that need more time. It includes:

• All checks from the Accurate strategy
• Extended wait times (5 minutes) for greylisted servers to respond
• Automatic retries when IP addresses are temporarily throttled by a mail server, waiting for cooldowns to expire rather than giving up
• More definitive results for domains that use greylisting or aggressive rate limiting

Best for: Lists where you want to minimize unknown results, and you’re willing to wait longer for more definitive answers.

Enhanced

The Enhanced strategy performs the most comprehensive validation of email addresses. It includes all the checks from the Thorough strategy, plus:

• Additional heuristics to improve detection accuracy
• Third-party data sources for cross-referencing
• More sophisticated validation techniques

Best for: Scenarios where accuracy is critical, such as validating high-value lead lists or when you need the highest confidence in your results.

Note: This strategy takes significantly longer to complete than the other strategies due to the additional checks and data sources involved.

Choosing the Right Strategy

When in doubt, use the Accurate strategy. It provides reliable results for most use cases. Switch to Fast when you need real-time performance, Thorough when greylisting is causing too many unknowns, or Enhanced when you cannot afford to have any invalid emails slip through.