Searches fail with error "Logon failure: unknown user name or bad password." (4218968)

The following is in the eventlog:
Event Type: Error
Event Source: Archive Manager Web
Event Category: None
Event ID: 1
Date: 19/12/2008
Time: 14:40:28
User: N/A
Computer: Quest1234

Description:
WWW.Search: [956129755-728026528-0-0x0] Error has been handled


Exception Source: AfterMail Business Layer
Exception Type: AfterMail.BusinessLayer.Remoting.FullTextSearchException
Exception Message: Logon failure: unknown user name or bad password.

Exception Target Site: SearchMessage
Date and Time: 19/12/2008 14:40:28
Machine Name:  Quest1234
IP Address: 192.168.1.23
Current User: Quest1234\ArchiveMgr_Service
CLR Version: 2.0.50727.3053
Platform (version): Win32NT (5.2.3790.131072)
Application Domain: /LM/W3SVC/2/Root-1-128741698936718750
Assembly Codebase: file:///C:/Program Files/ArchiveManager/Website/bin/AfterMail Common.DLL
Assembly Fullname: AfterMail Common, Version=4.0.5.126, Culture=neutral, PublicKeyToken=null
Assembly Version: 4.0.5.126

This issue is common in Groupwise where the service account specified is a local machine account and not a member of Active Directory.

The SQL server is on a different box to Archive Manager so the service account has no access rights to the SQL box

Use Pass Through authentication to fix this issue.

1. Create an account on the SQL box that has the exact same Username and Password as the service account on the Archive Manager box

2. Make sure this account is a member of the local admin group

3. Check this account has access to the Full Text Index Temp Path Share.