You can send invitation using custom from e-mail in the invitation e-mail.
IMPORTANT: You must setup SMTP settings in your Conference Proxy in order to test custom from setting. If you don't already setup it, please check here.
Step 1
In user settings under User management set setting Custom from for e-mails to "custom-from@islonline.com".
Step 2
Create new meeting and send invitation. If you don't know how to do that, please check here from step 3 to step 6.
Step 3
When you send invitation, "From" e-mail is the one you set in Custom from for e-mails in your user settings ("custom-from@islonline.com").