EMAIL BASICS — Recognizing a valid address format Which of the following strings is a correctly formatted e-mail address that could be used to send or receive messages on the Internet?

Introduction / Context:
E-mail systems require addresses to follow a specific pattern so that messages can be routed correctly through mail servers and domain name systems. Recognizing this format is essential for error-free communication.

Given Data / Assumptions:

• A valid e-mail address uses the local-part@domain pattern.
• The domain typically includes a top-level domain such as .com, .org, or a country code.
• We are choosing from similar-looking but incorrect strings (web URLs or malformed addresses).

Concept / Approach:
The general form is local-part@subdomain.domain.tld . The local part may include letters, numbers, and certain symbols. The domain must be a valid DNS name with a top-level domain. Thus, “professor@learnthenet.com ” is syntactically correct and points to the domain learnthenet.com.

Step-by-Step Solution:
Check for the @ symbol separating local part and domain.Ensure the domain contains a valid top-level domain (e.g., .com).Select the entry that satisfies both criteria.

Verification / Alternative check:
Mail clients validate addresses on send; DNS lookups and MX records for the domain determine actual deliverability, but the format remains as above.

Why Other Options Are Wrong:
professor.at.learnthenet — lacks @; uses dots in place of required separator.www.learnthenet.com — a web URL host, not an e-mail address.professor@learnthenet — missing top-level domain; incomplete.http://professor.learnthenet.com — URL with scheme; not an e-mail address.

Common Pitfalls:
Confusing web addresses (URLs) with e-mail addresses; adding “www.” or “http://” to e-mail addresses is invalid.

Final Answer:
professor@learnthenet.com