How can I identify misspelled email domains in my database?

Summary

Identifying misspelled email domains involves a multi-faceted approach, combining manual and automated techniques. Experts and marketers recommend utilizing services like Kickbox, Mailgun, Debounce, Verifalia, EmailHippo, and ZeroBounce, which offer real-time typo detection and validation through APIs, syntax checks, and domain analysis. Additional strategies include creating custom scripts for typo checks, employing regular expressions and dictionaries, and monitoring bounce rates for suspicious domains. Databases and systems can leverage data validation rules and lookup tables of valid domains. Monitoring for typo-squatting domains also helps prevent phishing. Finally, RFC standards provide syntax rules for basic validation. Proactive domain identification and removal are crucial for maintaining email deliverability.

Key findings

  • Real-Time Validation APIs: Services like Mailgun, Kickbox, Debounce, Verifalia offer APIs that provide real-time typo detection and email validation through syntax checks and domain analysis.
  • Custom Scripting and Regex: Creating custom scripts using regular expressions and dictionaries enables identifying common typos and variations in domain names.
  • Bounce Rate Analysis: Monitoring bounce rates for specific domains helps identify potential issues with misspelled or invalid addresses.
  • Database Validation: Utilizing data validation rules and lookup tables of valid domains within database systems can prevent misspelled domains from being entered.
  • Typo-Squatting Monitoring: Monitoring for typo-squatting domains, where attackers register common misspellings, protects against phishing and improves brand safety.
  • Proactive Domain Identification: Identifying and removing problem domains improves deliverability.

Key considerations

  • Cost of Services: The cost of using commercial email validation services needs to be considered against the potential ROI in improved deliverability.
  • Integration Complexity: Implementing and maintaining integration with validation APIs can be complex and require technical expertise.
  • Accuracy vs. False Positives: Balancing the accuracy of typo detection with the risk of flagging valid email addresses as false positives is important.
  • Data Volume and Scalability: Consider the volume of data and the scalability of the chosen solution as the database grows.
  • Ongoing Maintenance: Maintaining up-to-date typo dictionaries and validation rules requires continuous effort.
  • Compliance and Privacy: Ensure that data processing and storage comply with privacy regulations.

What email marketers say
7Marketer opinions

Identifying misspelled email domains in a database involves various techniques, ranging from manual methods to automated services. Marketers use methods like compiling domain lists with click activity, employing regular expressions and typo dictionaries, creating scripts for common typo checks, and segmenting lists to monitor bounce rates. Services like EmailHippo, ZeroBounce, and validation APIs offer real-time detection and correction, leveraging databases of valid/invalid emails and pattern recognition. Fuzzy matching algorithms can also be used to compare domains against known good domains.

Key opinions

  • Regex and Dictionaries: Using regular expressions and dictionaries of common misspellings helps identify potential typo domains, especially focusing on TLD errors.
  • Scripting and Validation: Creating scripts that check for common typos and comparing domains against known valid ones can flag mismatches.
  • Bounce Rate Monitoring: Monitoring bounce rates by domain helps identify those with a high prevalence of misspelled addresses.
  • Email Validation Services: Employing email validation services provides real-time detection and correction of misspelled domains during sign-up or data entry.
  • Fuzzy Matching Algorithms: Implementing fuzzy matching algorithms like Levenshtein distance compares email domains against a list of known good domains to highlight potential misspellings.

Key considerations

  • Data Volume: The volume of data in your database may influence the choice between manual and automated methods.
  • Real-Time vs. Batch: Consider whether you need real-time validation during sign-up or if batch processing for existing data is sufficient.
  • Accuracy: Evaluate the accuracy of different methods and services to minimize false positives and negatives.
  • Cost: Factor in the cost of email validation services and development effort for custom scripts.
  • Maintenance: Plan for ongoing maintenance of typo dictionaries and validation scripts to keep them up-to-date.
Marketer view

Email marketer from MarketingProfs advises segmenting your email list and monitoring bounce rates for each domain. High bounce rates for specific domains can indicate a high prevalence of misspelled addresses. She also suggests using a double opt-in process to reduce the likelihood of typo submissions.

July 2022 - MarketingProfs
Marketer view

Email marketer from ZeroBounce suggests employing an email validation service to remove invalid email addresses, including those with misspelled domains. They focus on identifying and flagging typo domains in real-time during sign-up or data entry.

December 2024 - ZeroBounce
Marketer view

Email marketer from Email Marketing Forum recommends creating a script that checks for common typos, such as missing letters or transposed characters in domain names. Additionally, they suggest comparing the domain against a list of known valid domains and flagging those that don't match.

May 2022 - Email Marketing Forum
Marketer view

Email marketer from EmailHippo explains that they maintain an extensive database of valid and invalid email addresses. They utilize pattern recognition and data analysis to detect suspicious or malformed email domains.

September 2023 - EmailHippo
Marketer view

Email marketer from Email Geeks shares their method of compiling a list of domains with clicks in the past year and filtering out those not in it, resulting in a list of over 150K domains, which may include typos and small domains.

October 2021 - Email Geeks
Marketer view

Email marketer from Reddit suggests using a combination of regular expressions and a dictionary of common misspellings to identify potential typo domains. They recommend focusing on common top-level domain (TLD) errors like ".con" instead of ".com".

September 2022 - Reddit
Marketer view

Email marketer from StackOverflow suggests implementing a fuzzy matching algorithm, like Levenshtein distance, to compare email domains against a list of known good domains and highlight potential misspellings based on a calculated difference score.

March 2022 - StackOverflow

What the experts say
3Expert opinions

Experts recommend various strategies for identifying misspelled email domains. Using services like Kickbox and monitoring for typo-squatting domains are useful. Proactively identifying problem domains associated with patterns such as high bounce rates allows you to improve deliverability by removing invalid or misspelled addresses.

Key opinions

  • Kickbox for Detection: Services like Kickbox offer typo detection to identify misspelled domains.
  • Typo-Squatting Monitoring: Monitoring for typo-squatting domains protects against phishing and malicious activities.
  • Bounce Rate Analysis: Analyzing bounce rates can indicate problem domains with typos or invalid addresses.

Key considerations

  • Service Costs: Consider the cost associated with services like Kickbox.
  • Proactive Monitoring: The importance of proactively monitoring your email list.
  • Deliverability Impact: Removing problem domains significantly improves email deliverability.
Expert view

Expert from SpamResource suggests monitoring for typo-squatting domains, where attackers register domains that are common misspellings of legitimate brands. Identifying these domains helps prevent phishing and other malicious activities that could impact email reputation.

June 2022 - SpamResource
Expert view

Expert from Word to the Wise explains the importance of proactively identifying problem domains within your email list. They recommend looking for patterns such as high bounce rates associated with specific domains, which can indicate typos or invalid addresses. They advise that removing these problematic addresses improves deliverability.

November 2024 - Word to the Wise
Expert view

Expert from Email Geeks suggests exploring a service like Kickbox for typo detection. They also share their experience of creating a large file of bad domains based on send errors.

August 2021 - Email Geeks

What the documentation says
6Technical articles

Various documentation sources highlight methods for identifying misspelled email domains, ranging from real-time API verification (Mailgun, Kickbox, Debounce, Verifalia) to database validation rules (Microsoft). API services use syntax checks, domain checks (including MX records), and typo detection algorithms to validate email addresses. Database systems leverage lookup tables of valid domains. RFC documents (RFC 1035, RFC 1123, etc.) specify syntax rules for valid domain names.

Key findings

  • Real-time API Verification: Email verification APIs (Mailgun, Kickbox, Debounce, Verifalia) offer real-time identification of misspelled domains using multiple validation techniques.
  • Database Validation Rules: Database systems (Access, SQL Server) can use data validation rules and lookup tables to check for domain misspellings.
  • RFC Domain Syntax: RFC documents (RFC 1035, RFC 1123, etc.) define the syntax rules for valid domain names.
  • Typo Correction: Verifalia contains an advanced typo correction engine which detects and suggests corrections for misspelled domains.

Key considerations

  • API Integration: Consider the complexity and cost associated with integrating email verification APIs.
  • Database Management: Maintaining accurate lookup tables of valid domains in database systems requires effort.
  • Syntax Compliance: Ensuring compliance with RFC syntax rules is a baseline validation step.
Technical article

Documentation from Kickbox details that their email verification service identifies invalid email addresses including those with misspelled domains. Their system checks for common typos and suggests corrections to the user, allowing for real-time correction and prevention of invalid entries.

July 2023 - Kickbox
Technical article

Documentation from Microsoft explains that one can use data validation rules within database systems (like Access or SQL Server) to check for common domain misspellings by referencing a lookup table of valid domains. This ensures only valid domains are entered.

October 2021 - Microsoft Documentation
Technical article

Documentation from Debounce shares that their service provides typo detection, identifying common misspellings in email addresses. They have a database of common domain typos that they use to flag and correct mistyped email addresses during verification.

December 2021 - Debounce
Technical article

Documentation from Verifalia highlights its advanced typo correction engine which can accurately detect and suggest corrections for misspelled domain names and local-parts. They maintain an up-to-date database with common domain name typos and their corresponding corrections.

May 2021 - Verifalia
Technical article

Documentation from Mailgun explains that their email verification API can identify misspelled domains in real-time. The API uses a combination of syntax checks, domain checks (including MX records), and typo detection algorithms to determine the validity of an email address.

September 2024 - Mailgun
Technical article

Documentation from RFC Editor specifies the syntax rules for valid domain names (RFC 1035, RFC 1123, etc.). These documents provide rules for validating that the structure and characters used in domain names are technically correct before additional typo-specific checks are implemented.

October 2021 - RFC Editor