Mike,

Check FAQ#8137

>Hi
>
>I've seen a little about this in other threads but no real soloution but perhaps I am missing something ?
>
>We are using fairly basic commands
>
>oform = CreateObject("form")
> oform.addobject("Session1","olecontrol","MSMAPI.mapiSession")
> oform.addobject("Message1","olecontrol","MSMAPI.mapiMessages")
>
>Anyway they fail with this Invalid Class String message on a number of PC's. The PC's are various Win 98 / Win 95 running Outlook 2000 or Express or Outlook 97. Its happened so far on 4 of the 6 PC's we've tried this application with.
>
>Originally I presumed that it was a problem with the PC's themselves but they do seem to contain all the MAPI DLL's etc... And these PC's are sending E-mails no problem in general.
>
>Any ideas for a way around this ?
>
>Is there some way to re-distribute and include in our Installation the required DLL files so that MAPI will work ?
>
>Thanks
>
>Mike