MDaemon's IMAP server in 13x supports the COMPRESS and BINARY extensions. The COMPRESS extension compresses all data sent to and from the client. This does require extra memory and CPU usage per IMAP session. The BINARY extension lets clients download message attachments in decoded form.
To enable/disable COMPRESS extension:
- Select Setup
- Select Server Settings
- Select Servers
- Check/uncheck ...IMAP server supports COMPRESS command