This article provides a link to a Plesk knowledge base article which explains how to retain log files older than a day. Editing the registry values explained in the article will prevent MailEnable log files that are older then one day from being removed.
Please visit the following link for information how to retain MailEnable log files that are older than one day:
|Product:||MailEnable (All Versions)|
|Class:||HOWTO: Product Instructions|
|Revised:||Friday, January 13, 2017|