Home
Challenges
Validate Email Formats
Cleanup
Easy

Validate Email Formats

An Excel email list contains questionable entries, and you need to flag which ones match a basic valid format.

AuthorExcelClash Team
PublishedApr 02, 2026
Validate Email Formats

The Problem

Email addresses can look close to valid while still being unusable. A missing @, a missing period, or an incomplete domain is enough to make a contact fail when the list is finally used.

This challenge uses a simple structure check to label each email as VALID or INVALID. It is not a full technical validation of every email rule, but it is a strong first cleanup step for messy contact data.

How We Solve It

The worksheet checks for two basic pieces: an @ symbol and a period. If both are present, the entry passes this simple format test. If either one is missing, the row is marked invalid.

Method 1: Search for the @ symbol

Search At Illustration
Method 1: Check whether the address contains the @ symbol.

SEARCH locates the @ inside the email text. On its own, this is only part of the rule, but it is a useful first check when diagnosing why a contact is broken.

This solves the first part of the validation problem because an email without an @ is immediately incomplete. It helps the sheet catch one of the most common formatting mistakes before the full rule is applied.

=ISNUMBER(SEARCH("@", B2))

Method 2: Combine the checks with AND

AND Logic Illustration
Method 2: Require both the @ symbol and a period in the text.

This is the pattern the solution uses. SEARCH checks for each required character, ISNUMBER converts the search results into TRUE or FALSE, and AND makes sure both tests pass before the row is treated as valid.

This solves the full challenge because the worksheet is using a two-part format rule, not a one-part check. The email only passes when both the @ sign and the period are present, which makes the result more useful than a single-symbol test.

=AND(ISNUMBER(SEARCH("@", B2)), ISNUMBER(SEARCH(".", B2)))

Method 3: Convert the result into labels

Audit Branding Illustration
Method 3: Turn the logical check into a clear validation label.

The final worksheet needs human-readable output, so IF wraps the logical test and returns VALID or INVALID. That makes the cleanup status easy to read and easy to count in the summary.

This solves the reporting side of the problem. Instead of leaving the result as TRUE or FALSE, the formula creates labels that are easier to scan in the table and easier to count in the invalid-summary cell.

=IF(AND(ISNUMBER(SEARCH("@",B2)),ISNUMBER(SEARCH(".",B2))),"VALID","INVALID")

Function Explanation

1. SEARCH

SEARCH finds the position of text inside another text string. In this challenge it looks for the required symbols inside the email address.

Learn more this functionSEARCH

2. ISNUMBER

ISNUMBER checks whether the search returned a numeric position. That is how the formula turns a successful symbol search into a logical TRUE result.

Learn more this functionISNUMBER

3. AND

AND requires both symbol checks to pass. It is what keeps the formula from approving an address that only has one of the two required parts.

Learn more this functionAND

This is a simple format check, not a complete email standard validator. It is useful for quick cleanup, but real-world email quality can still need stricter rules than just these two symbols.

Try Yourself

Check each email with the simple format rule, label it as valid or invalid, and then complete the summary so the worksheet shows the total number of contacts and how many invalid entries are in the list.

1
Objective #1
Cell: C2-C6

In Column C, identify if the email in Column B is "VALID" or "INVALID". An email is valid here if it contains an "@" symbol and a period.

2
Objective #2
Cell: B9

In cell B9, count the total number of contacts in your list.

3
Objective #3
Cell: B10

In cell B10, identify the total count of "INVALID" email addresses in your database roster.

Tactical Arena
Objectives Met: 0 / 0
Share this challenge
Share this challenge

Let others know about this challenge!

Related Challenges
Cleanup
#25
Extract First Word from Text

An Excel text list contains multi-word entries, and you need to pull the first word so the data is easier to group.

Easy
Cleanup
#26
Merge Multiple Columns into One

An Excel address sheet stores details in separate columns, and you need to combine them into one clean mailing line.

Easy
Cleanup
#27
Standardize Yes/No Responses

An Excel response sheet has mixed yes and no entries, and you need to standardize them into one clear format.

Easy
Cleanup
#28
Detect Invalid Phone Numbers

An Excel contact list has mixed phone formats, and you need to find which numbers are incomplete or contain invalid characters.

Easy
Discussion
0 Feedbacks
ExcelClash

ExcelClash is an interactive platform designed to level up your Excel skills through real-world exercises and challenges. Sharpen your logic, solve real spreadsheet problems, and learn faster—without boring lessons. Just hands-on practice that actually sticks.

Navigation
Back to Challenges
Go to Dashboard
Platform Home
Discover
SUM FunctionsLookup FunctionsConditional FunctionsLogical Functions
Support
About UsContact UsPrivacy PolicyTerms of Service
© 2026 ExcelClash, Inc. All rights reserved.
Objectives Met: 0 / 0