Does mail id contains capital letters
In general, email addresses (also known as mail IDs) can contain both lowercase and uppercase letters. However, there are some rules and conventions to keep in mind:
- Email address syntax: According to the Internet Engineering Task Force (IETF), the official standard for email addresses, the syntax allows for both lowercase and uppercase letters, as well as numbers, dots (.), hyphens (-), and underscores (_).
- Common practice: Most email providers and services, such as Gmail, Yahoo, Outlook, and others, allow and accept email addresses with both lowercase and uppercase letters.
- Case sensitivity: Email addresses are typically case-insensitive, meaning that the same email address can be written in different cases (e.g., "[email protected]" and "[email protected]" are considered the same email address).
- Best practice: To avoid confusion and ensure compatibility, it's generally recommended to use only lowercase letters in email addresses. This is because some older email systems or software might not be able to handle uppercase letters correctly.
In summary, while email addresses can technically contain both lowercase and uppercase letters, it's common practice to use only lowercase letters to ensure compatibility and avoid potential issues.