RTEditor/src/main/java/com/onegravity/rteditor/utils/validator/EmailValidator.java
public boolean isValid(String email) {
        if (email == null) {
            return false;
        }

        if (email.endsWith(".")) { // check this first - it's cheap!
            return false;
        }

        // Check the whole email address structure
        Matcher emailMatcher = EMAIL_PATTERN.matcher(email);
        if (!emailMatcher.matches()) {
            return false;
        }

        if (!isValidUser(emailMatcher.group(1))) {
            return false;
        }

        if (!isValidDomain(emailMatcher.group(2))) {
            return false;
        }

        return true;
    }
public boolean isValid(String email) {
        if (email == null) {
            return false;
        }

        if (email.endsWith(".")) { // check this first - it's cheap!
            return false;
        }

        // Check the whole email address structure
        Matcher emailMatcher = EMAIL_PATTERN.matcher(email);
        if (!emailMatcher.matches()) {
            return false;
        }

        if (!isValidUser(emailMatcher.group(1))) {
            return false;
        }

        if (!isValidDomain(emailMatcher.group(2))) {
            return false;
        }

        return true;
    }
<p>Checks if a field has a valid e-mail address.</p>

@param email The value validation is being performed on.  A <code>null</code>
value is considered invalid.
@return true if the email address is valid.