Announcement - Intra-domain email spoofing

Dear Valued Clients,

You received an incoming email that show sender is you and your colleagues ask you stop sending advertising email to them. Are you in the similar situation recently?
If yes, it is a type of Spoofing technique used by Spammer to use your email address in the 'From:' line of message.
Why they spoof your domain or email address?
1) Bypass SPF checking.
SPF is one of the method to fight again spoofing but if the sender is same domain as recipient (our clients) then it will bypass SPF checking because of Intra-domain communication.
2) Increase Inbox delivery.
Most of the recipient add their colleague email address or intra domain as trusted sender or bypass filtering rules.
Intra-domain also will skip from some spam score assigning in our mail server anti spams.
3) Increase the trust of victim.
Some of the recipient may not go through the content clearly but their trust level on sender in their contact list is higher compare to an email from unknown sources.
4) Reduce your domain reputation.
When your domain spoof by Spammer to blast around, it may cause your domain blacklisted in major Spam database that rate the reputation based on domain.
5) No reason
Some Spammer just target a random domain to attack without reason or gain anything from the Spoofing activity.
How can I prevent my domain use in spoofing activity?
I am sorry that there is no technology yet to avoid your domain used by the Spammer in spoofing activity.
Most of the domain owner will apply SPF record on their domain to reduce the damage of spoofing but it will only work if recipient mail server apply SPF checking.
What is the solution from Exabytes?
We apply SPF checking at SMTP level which will reject this kind of Intra-domain spoofing start from today: 16th Oct 2014, 11.00 AM GMT +0800.
Is my email account get compromised?
In most situation is no, you are just victim of spoofing.
What should I do when receive such email?
Kindly get the full email header of the original spoofing email and provide to our support team for further investigate:
What is the latest trend of spoof email?
Subject: Staff Wanted
Subject: New job offer
Subject: New employment opportunities 
Subject: Interesting Job
Subject: New Vacancies in our company
Subject: Employment invitation

You may refer the following link for more information regarding spoofing and email header:
What is Spoofing?
What is Email header?
Please do not hesitate to contact us by creating a Helpdesk Ticket at if you have any enquiries regarding email spoofing. Thank You!
Best Regards,
Support Team
Technical Department