Its called email spoofing attack. The sender address may look like your email address. But the header information contains original email address of the server they have used. You can ignore and avoid responding to prevent any further communication Ghazi.
About the code part in email footer, they may try to send some malware or it could be the signature hash algorithms attached by the email service provider for their reference. Just make sure you have an antivirus or internet security software installed in your system. Something like Kaspersky or bitdefender are good against online attacks.