ACSM (Adobe Content Server Message File)

The ACSM eBook file format

Files with an ACSM extension are closely related to Adobe Digital Editions. This product licensed by Adobe manages and reads eBook files as well as other file types for digital publications. However, ACSM files do not contain the eBook data itself. Instead, the information found in ACSM files is used to download, activate, and authorize the reading of eBook files.

Technical details of ACSM files

Adobe's Content Server sends the ACSM files directly to Adobe Digital Edition where they can be opened. When using another eBook reader, ACSM files may appear as well. This means that, before being able to correctly transfer the eBook to the device, Digital Editions has to be installed. Usually, ACSM files do not occur when downloading an eBook. If they appear on the computer however, it means that the download has been interrupted. It can be resumed by simply double-clicking on the ACSM file.

More information about the ACSM file format

File extension .acsm
File category eBook
Associated programs Adobe Digital Editions
Useful links Learn more about ACSM files and the Adobe Content Server
Developer Adobe