How do I validate the structure of an email account and what are some valid email address examples?
Summary
What email marketers say10Marketer opinions
Email marketer from MailerCheck emphasizes the importance of detecting disposable email addresses during email validation. These temporary addresses can lead to deliverability issues and skewed marketing metrics.
Email marketer from Kickbox emphasizes the importance of email validation to maintain a clean email list, improve deliverability, and protect sender reputation. They explain that validating emails helps prevent bounces, spam complaints, and blacklisting.
Email marketer from Email Hippo suggests implementing real-time typo detection as users type their email addresses. This helps prevent common errors like misspellings and missing dots, ensuring more accurate email capture.
Email marketer from Super User points out that many email services support plus addressing (e.g., yourname+keyword@example.com), which can be useful for filtering and tracking. However, overly strict validation might reject these valid addresses.
Email marketer from Email Geeks shares a trick to create valid email addresses using '+something' with Gmail, routing all incoming mail to the base address. For example, <mailto:example+this@gmail.com|example+this@gmail.com> and <mailto:example+that@gmail.com|example+that@gmail.com> will both route to <mailto:example@gmail.com|example@gmail.com>.
Email marketer from Medium explains that valid email addresses can contain a wide range of characters, including alphanumeric characters, periods, underscores, plus signs, and hyphens, in the local part before the @ symbol. The domain part should follow standard domain naming conventions.
Email marketer from Reddit recommends sending a confirmation email as the best way to validate an email address. This confirms the email exists and the user has access to it, rather than relying solely on syntax checks.
Email marketer from example.com shares common valid email address examples such as <mailto:firstname.lastname@example.com|firstname.lastname@example.com>, <mailto:email@subdomain.example.com|email@subdomain.example.com>, <mailto:email@123.123.123.123|email@123.123.123.123>, and <mailto:email@[2001:db8::1]|email@[2001:db8::1]>, highlighting various allowed formats.
Email marketer from NeverBounce explains that a correctly formatted email address consists of a local-part, the @ symbol, and a domain. The local-part can contain alphanumeric characters and certain special characters, while the domain must be a valid domain name.
Email marketer from Stack Overflow shares a detailed regular expression for validating email addresses, accounting for various valid formats, and explains the nuances of email address syntax according to RFC specifications.
What the experts say4Expert opinions
Expert from Word to the Wise (Laura Atkins) explains that modern email address syntax is incredibly complex, allowing for various special characters and even internationalized characters. She recommends against trying to validate addresses with overly strict regular expressions and suggests focusing on deliverability checks instead.
Expert from Email Geeks explains that most of the provided email examples are syntactically valid, even if they are not deliverable. He also states you can have full unicode in the domain part of email addresses, including internationalized TLDs.
Expert from Email Geeks shares a link to an article that might be helpful for understanding email address structure: <https://wordtothewise.com/2009/03/what-is-an-email-address-part-three/>
Expert from Word to the Wise (Laura Atkins) suggests that the most reliable way to validate an email address is to send a test email and check for bounces. This verifies that the address exists and is accepting mail.
What the documentation says4Technical articles
Documentation from OWASP advises against strict email validation using regular expressions, highlighting the complexity of email address syntax and the risk of rejecting valid addresses. It suggests using a more relaxed pattern or relying on email confirmation.
Documentation from ietf.org defines the Internet Message Format, detailing the syntax for email addresses, including local-part and domain structure, allowed characters, and the use of quoted strings and comments.
Documentation from Verimail explains that email validation services check email addresses at multiple levels, including syntax, domain existence, mailbox existence, and spam trap detection, to ensure high deliverability and data quality.
Documentation from MSDN explains how to validate an email address using regular expressions in .NET. The expression checks for a valid local part, @ symbol, and domain. It also discusses some limitations, such as not checking for valid TLDs.