One variation of a method for verifying email senders includes: intercepting an email addressed to a target recipient within an organization, the email received from a sender at an inbound email address and including an inbound display name; accessing a whitelist including a verified display name and a set of verified email addresses corresponding to an employee within the organization; characterizing a display name difference between the inbound display name and the verified display name; in response to the display name difference falling below a threshold difference, comparing the inbound email address to the set of verified email addresses; in response to identifying the inbound email address in the set of verified email addresses, authorizing transmission of the email to the target recipient; and, in response to the set of verified email addresses omitting the inbound email address, withholding transmission of the email and flagging the email for authentication.