In ALM, the Automail feature is designed to send emails out to specified users when changes are made to specified defects. You will need to utilize workflow script to perform this functionality. I have created the following workflow script that will notify the specified user when a field value is changed within the Test Plan module. The example below sends an email when the value in the 'Status' field is changed. It can be edited to work with any of the other fields within the Test Plan module.

You will need to enter the script into the 'Test Plan module script' within the 'Script Editor'.
Location of the Script Editor - Go to 'Customize' --> Workflow --> Script Editor --> Expand 'Test Plan module script...

Enter the script below into the 'Sub Test_FieldChange' function...

Sub Test_FieldChange(FieldName)
'On Error Resume Next
Dim strSubject, strDes
Set tdc = TDConnection
If Test_Fields.Field(''TS_STATUS'').IsModified Then
strSubject = ''Test Change Notification'' & '' for the '' & tdc.ProjectName & '' project in the '' & tdc.DomainName & '' domain. ''
strDes = ''The user '' & User.FullName & '' has changed the status of the '' & Test_Fields.Field(''TS_NAME'').Value & '' test to '' & Test_Fields.Field (''TS_STATUS'').Value
tdc.SendMail ''specified_user_email@testmail.com'', '''', strSubject, strDes, NULL,''HTML''
'Set TDConnection = nothing
End If
'On Error GoTo 0
End Sub