The present invention relates to a method and system that audits email marketing campaigns. The system may include an audit SMTP server and an audit processor. The audit SMTP server may be configured to receive and store email messages transmitted over a public network and addressed to a designated email inbox at the audit SMTP server established for performing quality diagnostics. The received email messages were generated at a source email SMTP server and include a plurality of parts. The audit processor may be configured to parse the individual received email messages into parts and apply a group of different performance processes to the different parts. The audit processor may be further configured to produce and store output data generated from the performance processes that identifies quality characteristics in the different parts that represent faults that will occur from the use of the template in an email marketing campaign.