Unable To Send Databasemail On A Clustered Environment

I am able to send databasemail on my staging servers which are non clustered but databasemail fails on my clustered production servers.
Both production and staging servers sit on the same domain(although the domain controller is sitting on one of the staging servers)
I have set up the account and profile and have double checked that it is pointing to the correct SMTP server and to the same one as the staging servers.
I have also enabled database mail in surface area configuration.
The message gets queued, because i see the 'mail is queued' message.
The databaseMail Process also gets started, but during the actual send process I see
The following is the error in the databasemail log.
Any ideas what could be my problem?


Databasemail Log

Date 18/07/2007 18:49:17
Log Database Mail (Database Mail Log)

Log ID 14
Process ID 964
Last Modified 18/07/2007 18:49:17
Last Modified By TT-IXTOOLSixtools

Message
1) Exception Information
===================
Exception Type: System.NullReferenceException
Message: Object reference not set to an instance of an object.
Data: System.Collections.ListDictionaryInternal
TargetSite: Microsoft.SqlServer.Management.SqlIMail.Server.Objects.Account GetAccount(Int32)
HelpLink: NULL
Source: DatabaseMailEngine

StackTrace Information
===================
at Microsoft.SqlServer.Management.SqlIMail.Server.DataAccess.DataAccessAdapter.GetAccount(Int32 accountID)
at Microsoft.SqlServer.Management.SqlIMail.Server.DataAccess.SessionManager.GetAccount(Int32 accountID)
at Microsoft.SqlServer.Management.SqlIMail.Server.Controller.CommandFactory.CreateSendMailCommand(DBSession dbSession)
at Microsoft.SqlServer.Management.SqlIMail.Server.Controller.CommandRunner.Run(DBSession db)
at Microsoft.SqlServer.Management.SqlIMail.IMailProcess.ThreadCallBack.MailOperation(Object o)

btw, I ran this command to send mail

declare @body1 varchar(100)

set @body1 = 'Server :'+@@servername+ ' My First Database Email '

EXEC msdb.dbo.sp_send_dbmail @recipients='mytestemail@email.com',

@subject = 'My Mail Test',

@body = @body1,

@body_format = 'HTML' ;