We have things like our "Verified Sender" list, which includes companies like:
Fedex, DHL, UPS, PayPal, Amazon, DocuSign, eFax, RingCentral, HSBC Bank, BankofAmerica, Wells Fargo, Sam's Club, CostCo, USPS, CitiBank, Chase Bank, ADP
(and many many others)
When they send you a mail message, we mark it with a Green Checkmark, meaning it is safe to open.
Messages that pretend to be from these same senders, but are fakes, are tagged with our "Possible Phishing" warning.
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Read more about Verified Senders