== System properties

Some tuning can be done via system properties. This includes:

.System properties
|===
| Property name | explanation

| james.message.memory.threshold
| (Optional). String (size, integer + size units, example: `12 KIB`, supported units are bytes KIB MIB GIB TIB). Defaults to 100KIB.
This governs the threshold MimeMessageInputStreamSource relies on for storing MimeMessage content on disk.
Below, data is stored in memory. Above data is stored on disk.
Lower values will lead to longer processing time but will minimize heap memory usage. Modern SSD hardware
should however support a high throughput. Higher values will lead to faster single mail processing at the cost
of higher heap usage.


| james.message.usememorycopy
|Optional. Boolean. Defaults to false. Recommended value is false.
Should MimeMessageWrapper use a copy of the message in memory? Or should bigger message exceeding james.message.memory.threshold
be copied to temporary files?

|===