You should look into the COBRAS tool for this. There may be some caveats so you NEED to read the help file and be familiar with tool and any limitations first. However, COBRAS backup is supported for Unity 4.0(5), 4.1(x), 4.2(x), 5.0(x), 7.0(x) or 8.0(x) with Exchange or Domino as the back-end. However, you cannot import to a Domino-based system. Since you are moving to VMO, I'll assume the back-end will be Exchange. So,
COBRAS import is supported on Unity 4.0(5), 4.1, 4.2, 5.0, 7.0 and 8.0 with Exchange as the back end. No support is planned for import into any version of Unity with Domino as the back end given limitations imposed by IBM on the DUC interface. Export from system connected to Domino is supported, however. This would be an ideal tool for you to use in this situation. Read up on it here:
http://www.ciscounitytools.com/Applications/General/COBRAS/Help/COBRAS.htm#_Toc260901105
Hailey
Please rate helpful posts!!!