AS2 File Transfers

What is AS2 and how is it used to send and secure critical file transfers? Explore everything you need to know about the Applicability Statement 2.

An Introduction to AS2

What is AS2?

AS2 (Applicability Statement 2) is a popular protocol specification that’s used to transmit sensitive data securely and reliably over the internet. Upgraded from the original protocol (AS1) that was created in the 1990s, AS2 supports the encryption of messages (also known as AS2 messages) that are then exchanged with trading partners and vendors via HTTPS. These messages are built using the S/MIME format.

How Does AS2 Work?

AS2 utilizes digital certificates and encryption standards to protect critical information while it’s in transit across systems, networks, and locations. AS2 messages can be compressed, signed, encrypted, and sent over a secure SSL tunnel

Users can also request an MDN (known as Message Disposition Notification; also sometimes referred to as "receipt") alert to verify that the message was received and decrypted successfully. Using signed receipts to compare the returned message checksum value creates a non-repudiation of receipt (NRR). An NRR gives the sender legal proof of unaltered delivery.

MDNs can be delivered in a variety of ways, including:

Synchronous MDN

Asynchronous MDN

Email MDN

Synchronous MDN

This option allows the AS2 server connection to remain open until an MDN is received or a timeout occurs.

Synchronous MDN

This option allows the AS2 server connection to close immediately after the initial transmission completes. When the server processes the AS2 message, the server will open a new connection and send the MDN.

Why Use AS2?

AS2 is a secure industry standard protocol for sending sensitive data. Organizations who use AS2 often choose it over other file transfer protocols (like FTP or SFTP) because of how easily the protocol helps them meet regulatory compliance requirements and trading partner needs.

AS2 comes with unique advantages that ensure the streamlining of critical data exchange.

A few benefits of using the AS2 protocol:

End-to-end encryption for sensitive files

Authenticating senders and recipients with digital signatures

Validation of file integrity with successful transfer confirmation

Ability to send/retrieve file transfers of any size or volume

Flexible support for synchronous or asynchronous MDN receipts

AS2 and Drummond Certified


You may have heard of the phrase "Drummond Certified." What does Drummond Certified mean, and why is it important for AS2 file transfers?

Drummond Certified is a label that Drummond Group (a third-party certification body) gives to products and solutions that have proven their interoperability between AS2 vendors. The certification is extensive and helps ensure that the solution you use will allow you to successfully integrate with your AS2 trading partners.

In order to pass the Drummond Certification process, any product attempting certification has to conduct thousands of AS2 protocol test scenarios successfully. This process uses full matrix interoperability testing between AS2 vendor solutions to verify that important transactions maintain their security and integrity as they are transmitted over the Internet.

Getting Started with AS2 File Transfers

Whether your trading partners require you to send files using AS2 or you’re looking for an industry standard protocol to transmit sensitive files that meet regulatory compliance, it’s easy to implement AS2 in your organization. You just need the right solution.

GoAnywhere MFT is a secure managed file transfer solution that simplifies, streamlines, audits, and automates your file transfers across a variety of environments. It provides AS2 client and AS2 server software for small, medium, and enterprise-level organizations.

"We were looking for an off-the-shelf implementation of an AS2 Server and Client that we could easily integrate with our systems on AWS [Amazon Web Services.] GoAnywhere was the perfect match."

The AS2 Client

The AS2 client software in GoAnywhere can automate the delivery of AS2 messages or send AS2 messages on a scheduled basis. It can automatically reconnect to the server if a connection breaks and retransmit the message. Both synchronous and asynchronous receipts can be logged to ensure AS2 messages were successfully processed by the trading partners.

Learn more about our AS2 client

The AS2 Server

The AS2 server software in GoAnywhere allows you to receive AS2 messages. Your trading partners can be authenticated using a combination of user credentials and X.509 certificates. When a message is received, you can have a trigger automatically process the received files. (For instance, GoAnywhere could move the AS2 documents to another area on the network or call an application to process these files.)

Learn more about our AS2 server

Start Using AS2 for File Transfers Today

Need to transfer files with AS2? See how easy it is to implement secure AS2 file transfers in your organization with a free, 30-day trial of GoAnywhere MFT.