Electronic receipt-linking database system

A system, comprising:

• a processing device communicatively couplable to an electronic mail (email) server having a common inbox for storing a plurality of email messages received in the common inbox based on a domain part of corresponding email addresses for the plurality of email messages;
• a memory device accessible to the processing device and including instructions executable by the processing device to cause the processing device to:
• retrieve the plurality of email messages from the common inbox;
• determine an account holder associated with an email message of the plurality of email messages using a local part of an email address corresponding to the email message;
• identify receipt content within the email message, the receipt content corresponding to a receipt for a transaction between the account holder and a third party using an account associated with the account holder;
• extract metadata from the email message, the metadata being different than the receipt content for the transaction, and the metadata including a timestamp corresponding to a date and time that the email message was received by the email server or stored in the common inbox;
• generate an electronic document including the receipt content and having a format displayable to the account holder on a user device communicatively coupled to the processing device via a network;
• identify, using the timestamp in the metadata, a secure record of the transaction stored in a database having account information associated with the account, the account information including a plurality of secure records corresponding to a plurality of transactions and stored authentication information;
• associate the receipt content, the metadata, and the electronic document with the secure record;
• and
• authenticate the account holder to allow the account holder to view, on the user device, the secure record and the electronic document by comparing the stored authentication information with authentication information received from the account holder via the user device.