Paymail is a practical implementation of the family of related protocols collectively referred to as BSVAlias. In brief, it is an identity protocol that removes Bitcoin addresses from the user experience. Instead of addresses, Paymail uses human-readable names that look exactly the same as email addresses. Paymails are much easier to type into a device than Bitcoin addresses and can be used to identify an individual via the Paymail identifier.

The protocol describes a procedure where a wallet provider will be able to be discovered and contacted, and can respond to payments and payment requests in real time so that payment receivers don’t have to re-use their Bitcoin addresses, thereby maintaining privacy.

As a simplified example, in order for Alice to send some bitcoin to Bob, Alice sends the payment to Bob@paymail.com. The paymail protocol implemented by Bob’s wallet will provide a Bitcoin script to pay to for the actual Bitcoin transaction creation rather than relying on the concept of the Bitcoin address which is actually just a compact encoding of a script but limits the form of the script to one particular type. This is done behind the user experience. Note that the security will rely on a public key infrastructure.

At the time of writing, the protocols cover:

BRFC Specifications
Service Discovery
Public Key Infrastructure
Payment Addressing

For more information visit the BSVAlias website.

Paymail is the name for the implementation of the following protocols:

Service Discovery
Public Key Infrastructure
Basic Address Resolution from the Payment Addressing protocol group

The Paymail brand is reserved for products and services that, at a minimum, implement each of the above protocols.

Moneybutton has published content describing Paymail and why it is needed here

https://wiki.bitcoinsv.io/index.php/Paymail

Overview

paymail is a collection of protocols for Bitcoin SV wallets that allow for a set of simplified user experiences to be delivered across all wallets in the ecosystem.

❌ No more complicated 17Dx2iAnGWPJCdqVvRFr45vL9YvT86TDsn addresses

✅ Simple payment handles like <alias>@<domain>.<tld>

The goals of the paymail protocol are:

User friendly payment destinations through memorable handles
Permissionless implementation
Self-hosted or delegated to a managed service
Automatic service discovery/location
PKI infrastructure
Cross-wallet exchange of single-use transaction output scripts of any construction
Request and response authentication
Security and policy management
Capability extensibility and discovery

bsvalias

The family of related protocols are collectively referred to as the bsvalias protocols. At the time of writing, these include:

paymail

paymail is the name for the implementation of the following protocols:

Service Discovery
Public Key Infrastructure
Basic Address Resolution from the Payment Addressing protocol group

The paymail brand is reserved for products and services that, at a minimum, implement each of the above.

Extension Protocols

As defined in the BRFC Specifications, anybody can propose an extension to the bsvalias and paymail protocols, and as per the Capability Discovery section of the Service Discovery protocol, implementations can declare support for extensions to allow for cross-wallet processes.

Extension protocols are the collection of protocols not contained within the core paymail set defined above, but that are fully compatible with bsvalias protocols and paymail implementations. Notable examples presently include: