Fastmail is an independent email and productivity service operated by Fastmail Pty Ltd, offering fast, private email hosting for individuals and businesses. Its core products include email, calendars, and contacts, accessible through native apps across devices and available offline. Users can host email on their own domain, create aliases and Masked Email addresses, organize messages with powerful search, pin or snooze emails, and schedule messages to send later. Calendar features include event updates and the ability to bring Google or iCloud calendars together in one view.

Fastmail is a paid service, with no advertising or personal-data mining, and offers a 30-day free trial. It emphasizes email security, data privacy, reliable service, and personal support available 24/7. The company also provides tools and guidance for migrating mail, calendars, and contacts from services such as Gmail, Outlook, Yahoo, Proton, and HEY. For businesses, it offers email hosting and support, alongside resources including a help center, blog, podcast, and API documentation. Fastmail also contributes to open standards, including JMAP, and open-source software.