Solution : https://service.sap.com/sap/support/notes/660358 (SAP Service marketplace login required)
Key words : 
solution crm ic webclient toolbar profile, symptom e-mail related buttons, e-mail related buttons moved, ic webclient toolbar profile, e-mail viewset, e-mail relatedbuttons, refer toe-mail, 'default_call_list'  toolbar profile, email layout id', toolbar profile
Related Notes : 
       
| 696262 | CRM 4.0 SP Stack 1/2004 (SAPKU40004): Release & Info. Note | 
| 677456 | SAPKU40003: Support Package 03 for CRM 4.0 |