Modifying the Maximum Memory Available to the Mail Express Server


  • Mail Express, version 3.x


By default the Mail Express Server is limited to using up to 512MB of system RAM. While idle, the Mail Express Server will typically use far less than the maximum available memory. However, under peak load, the Mail Express Server will attempt to take full advantage of this available memory to maximize performance.

The default setting of 512 MB will typically suffice for average load systems. However, some of the following situations may warrant increasing the maximum memory available to the Mail Express Server:

  • A site experiences a higher-than-average number of package transfers per day
  • A site experiences transfer of larger-than-average package transfers per day
  • The Mail Express Server fails to respond in a timely manner when accessing the various web interfaces
  • The Mail Express Server experiences ERROR messages indicating that the Java Virtual Machine has run out of Java Heap Space. Such ERROR messages will typically contain the following text: java.lang.OutOfMemoryError: Java heap space
  • There is a large amount of unused system RAM available on the computer of which you would like to take better advantage

To increase the amount of system RAM that may be used by the Mail Express Server use the following instructions:

  1. Shut down the Mail Express Server Windows service.
  2. In a text editor such as Notepad, open the configuration file <Install Directory>\conf\MailExpressServerService.conf, where <Install Directory> is the installation directory of the Mail Express Server. By default "C:\Program Files\GlobalSCAPE\MailExpress."
  3. Locate the following line:
  4. Change "512" to the number of megabytes (MB) that you would like to make available to the Mail Express Server. For example: would allow the Mail Express Server to use up to 1024 MB (1 GB) of RAM when under peak load.
  5. Save the changes to the configuration file.
  6. Start the Mail Express Server Windows service.