Hi Åge,

Thanks for your question. When you invite users click on the Email addresses link and you can choose from contacts and members in other projects. That should give you quite an extensive list.

If a member wants, they can go in under personal preferences and add one or more aliases to their account. Then any invitation sent to any of those email adresses would end up for the same account. You can read how this is done in our knowledgebase:
http://support.projectplace.com/index.php?_m=knowledgebas...

Best regards,
Karolina