Spam cam easily be identified once you understand some key elements of spam messages.
A real life example of a scam sent to my gmail account.
Dear Gmail customer,
From now if you need more than 2 GB of space use this invitation and upgrade your account to 100 GB of space also you can register one free domain name via this invitation your account upgrade will done after 24 hours
Your invitation code is : (I edited link here so it is not clickbable)
Thank You
Gmail Support Department
You can easily understand it is spam just by reading the email. Gmail, Google company will also write email addressing you by your name. Dear Gmail customer, is a sign it is absolutely spam. Second all links should be on the Google domain. For example: Google.com/gmail and not
Finally try to use more common sense. Gmail will not email you personally to give you an invitation code. If they have invitation codes they will probably put something new on their site to inform everyone.
These are most common types of scams everyone receives:
People selling you any type of
1) weight loss products.
2) love/romance/relationship related products.
3) making money, lottery winnings.
4) emails stating a friend send you a greeting card.
5) gambling/Pharmacy products.
General rule is never trust emails that are trying to sell you something or if you do not know who the sender really is. Does he or she call you by your name? The answer is no if it is spam.
These are all real scam emails, their subject lines (to get an idea):
    Order Royal repl1ca w4tches Online
    Neighbor sent you a postcard from BlueMountain.Com!
    100mg x 90 pills $1.78 per pill
    Best Selection of Tag Heuer
    URGENT: Earn $500 (net income) over and over again! But, act fast!
By the way, if you never opted in to receive such emails they are 110% fake emails. (spam or scam call them what you want, they should be ignored and deleted) If you never opted in for a weight loss newsletter, ezine or whatever than all weight loss related emails can be marked as spam.
Finally make use of a spam blocker cause they identify spam very fast. They save time and improve your security.