Your ESP’s support team told you the emails were delivered. Your dashboard shows a 99% delivery rate. But revenue from email dropped 30% last quarter. These two facts are not contradictory – they are the exact gap an email deliverability consultant exists to explain. Delivery rate measures whether a server accepted your message. Inbox placement […]

SendPost analyzed 4 billion messages across 2025, and the headline number is blunt: emails with all HTTPS links hit a 98.1% delivery rate, while a single HTTP link in the body caused a measurable drop. LB Blair and Varun Jain presented the dataset at the Deliverability Summit 2026 in Barcelona, and the takeaways reshape what […]

At Deliverability Summit 2026 in Barcelona, Syed Alam of Postmastery walked through a dataset where roughly 18% of addresses suppressed under a standard hard/soft model were still valid recipients. They had been removed because a 5xx code looked terminal, or because a 4xx kept repeating. Both assumptions were wrong, and both were costing senders revenue […]