File contention may cause corruption to MailEnable configuration files.


Some MailEnable configuration files (eg: AUTH.TAB and/or ADDRESS-MAP.TAB) lose data or contain corrupt information.


Corruption of the file could be related to contention in accessing the file.

Please see below relating to potential causes of such contention:

1. A control panel application is directly editing the configuration files or has an error that is leading to the contents of the file being deleted. This contention can lead to corruption/data loss.

Example: Some control panel applications make changes directly to these files and this almost certainly will cause corruption when concurrent access to the files occurs.

2. Some resident / realtime antivirus protection products may causes contention/corruption where the server is under load. Some antivirus agents intercept the changes to the file, potentially causing contention issues.

3. File contention can occur where a large number of users attempt to make configuration changes concurrently.  In this case, there are some settings that can be applied to increase the timeout period.  This could occur when hosting over 5000-10,000 mailboxes.


Review the system to determine what could be causing the contention and, if possible, attempt to eliminate it. For example, if resident antivirus is being used, configure the antivirus application to exclude the MailEnable CONFIG directory from real-time protection.

Review the Windows Event Log for evidence of timeouts or contention when writing to these files. If MailEnable detects a timeout, it will record this to the Windows Event log.  Consequently, review/increase the registry keys associated with MailEnable's TAB delimited configuration files. These settings are configured in the registry under the following key:

HKEY_LOCAL_MACHINE\SOFTWARE\Mail Enable\Mail Enable\Providers

As a preliminary test as to whether the contention is the cause, modify (double) the current values and take note as to whether this alleviates the corruption.

The following document outlines these keys and their function:


Please also see: How to recover configuration data if a system corruption occurs or is accidently deleted?

Product:MailEnable (All Versions)
Keywords:corruption,,, configuration files, corrupt, lose data
Class:PRB: Product Problem or Issue
Revised:Wednesday, May 4, 2016