Users not receiving work items in Outlook

Hi All,

I am working on a standard workflow WS20000077 which is for overall release of Purchase requisition and this would be triggered when PR is released (RELEASESTEPCREATED event). Issue is when the PR is released, second approver receives the mail (work item) to release the PR in both SAP Inbox and Outlook, whereas third approver receives the work item only in his SAP Inbox and could not receive it in Outlook.

Could you please suggest whether this issue is related to Workflow or what could be done to solve this.

Thanks,

Priya