Postmark

The introduction of postage stamps in the 1840s necessitated a way to cancel them, leading to standardized postmarks.

The Ultimate Guide to Postmarks: History, Types, and Modern Significance

Postmark feels like it was built by people who have struggled with buggy email APIs. postmark

Postmark provides a suite of tools designed with the developer experience in mind.

Stop using your marketing ESP to send critical transactional emails. You are mixing gold (login verifications) with lead (bulk offers). The introduction of postage stamps in the 1840s

6. Postmarks in the Digital Age: The Electronic Postmark (EPM)

Postmark uses "Servers" to organize your emails by project or environment (e.g., Development vs. Production). Stop using your marketing ESP to send critical

In the legal world, the date on a postmark is king. The "Mailbox Rule" (common in contract law) states that a document is considered filed or accepted on the date it is , not the date the recipient receives it. If your tax return is due on April 15th, as long as the postmark on the envelope reads "April 15th" (or earlier), the IRS considers it on time—even if it arrives a week later. This single stamp prevents millions of dollars in late fees annually.