Implement email validation by trimming any leading and trailing spaces from the string. Then, check the email's validity based on three conditions: there must be characters before the @ symbol, there must be characters after the @, and the domain after the @ must contain a dot. If the email is valid, extract and display the domain (the part after the @ symbol, excluding the symbol itself).

1. In the validateEmail method, find the index of the @ symbol in the email.
2. In the validateEmail method, find the index of the last dot (.) symbol in the email.
3. Check that the @ index is greater than 0, and the dot index is greater than the @ index and less than the length of the email minus 1.
4. In the extractDomainFromEmail method, find the index of the @ symbol in the email.
5. Extract and return the substring starting from the character immediately after @ in the extractDomainFromEmail method.
6. In the main method, trim any leading and trailing spaces from the email string.