There is a big difference when sending an email to a large group of people using Outlook (or any other email clients), and when using GlobalSignIn’s email blasting technology. For one thing, GSI makes sure your emails are sent out fast. GSI also ensures that your emails get delivered safely into your recipients’ inbox. Email getting trapped as spam is a big problem these days. GlobalSignIn has implemented cutting-edge technology, which ensures high deliverability rate of emails.
For the technically inclined:
GSI’s email blasting technology implements Yahoo DomainKeys, Sender Policy Framework (SPF) and Sender ID. These are email authentication standards which helps differentiate between valid emails and spam.
More technical information:
DomainKeys, SPF, and Sender ID differ in technical specification but share the end-goal of minimizing the forgery of email messages. DomainKeys is a cryptographic-based authentication technology developed by Yahoo, in which signatures are inserted into every message allowing receivers to verify the original sender and guarantee that the message’s content has not been altered while in transmission.
Sender ID and SPF are IP-based authentication methods which verify that every email is truly from the Internet domain from which it claims to have been sent. This is done by checking the address of the server sending the mail against a registered list of servers that the domain owner has allowed email to be sent from. This makes it easy to stop most forged "From" addresses in email, helping to counter simple spoofing to complex phishing attacks.

