No offline approval mail being generated/sent for particular user

Hi Experts,

We have offline approval program /SAPSRM/OFFLINEAPPROVALSEND schedule to send the notification for pending work items.

But the mail is not being generated for one of the user.

We have checked the mail ID in SU01, BP, outlook and there is no difference. Attribute FORWARD_WI is 'X'.

The mail has been sent to previous approver and next approver for the same shopping cart in the hierarchy as it is multi-level approval cart.

Please suggest possible reason for this issue and how we can trouble shoot?

I have gone through below scn threads but did not find reason.

How to run the offline approval sending report for only one workitem - Supplier Relationship Management - SCN Wiki

Troubleshooting: Problems with offline approval email sending - Supplier Relationship Management - SCN Wiki

Best Regards,

Siddappa