Relevant Product: Mail Archiver
Check the index is on a local hard drive, SCSI drive or other high speed disk. An SSD drive will provide optimal performance for the index. To test this, copy a file (ideally around 10MB) to and from the location and ensure it copies quickly.
Defragment the index - this will reduce it in size and make searching quicker. This may take some time depending on the amount of fragmentation.
Check the Windows System Event Log to ensure there are no errors from NTFS or other disk services that indicate a read/write fault to the disk. If the drive is on a network, you may need to check the remote computer. If the drive is in a SAN/NAS, you will need to check your diagnostic software.
Use the Index Maintenance option to see what the index is currently doing. If it is doing a defragment/rebuild/resynchronize, expect search performance to be slightly slower than under normal operation.
Mail Archiver is installed on a client operating system (OS) such as Windows 7. This limits the number of IIS connections to ten, which can cause slow behavior if many users perform searches simultaneously. Errors will appear in the Application Event Log on the computer running Mail Archiver if this is the case. The only workaround is to install the software on a server OS such as Windows Server 2008 R2.
If a NAS/SAN is used, network throughput could be the cause. Monitoring the network connection at both ends to ensure the network link is not fully saturated will help ascertain if this is the case in your environment.