message failing in outbound status

hi all,

we have SNC - ECC scenario( Proxy to IDoc)

the message is successful in PI i.e. it has black checked flag in status coloumn,But in Outbound status coloumn it has red flag.

no messages struck in smq1, smq2 and sm58 (both on ECC side and PI side).

The IDoc is not reaching the target system i.e we cannot see any IDocs in we02.

can anyone please tell me how and where do we see the error details for such messages?

Regards,

Aditi.