After upgrading GroupWise 7.03 to 8.00hp2, e-mail to some (not all) mail servers give back a Send Failure: 501 5.5.4 Invalid Address

When I put the GWIA 7.03 back in the system, things work fine.

Some body an idea to fix this problem, or just run 7.03 GWIA till next service pack ?

14:10:40 07F DMN: MSG 30180 Sending file: HQNWCN01\GWIA_V1:\GWISE\D_GWI1\WPGATE\GWI1\send\pa 7adab2.005
14:10:40 07F DMN: MSG 30180 Attempting to connect to mail.odiris.nl (81.175.112.229)
14:10:40 07F DMN: MSG 30180 Connected to [81.175.112.229] (mail.odiris.nl)
14:10:40 07F DMN: MSG 30180 Send Failure: 501 5.5.4 Invalid Address
14:11:10 05B MSG 30180 Command: odiris.nl
14:11:10 05B MSG 30180 Response: 220 ************************************************** ************************************************** ***********
14:11:10 05B MSG 30180 Deferring message: HQNWCN01\GWIA_V1:\GWISE\D_GWI1\WPGATE\GWI1\defer\s a7adab2.005