The error states that a MAPI account ,outlook or whatever, is needed..., but this is becouse the sending method you had selected (e-mail send method) perhaps is not what you need, change it to "Email (SMTP) send" and retry.
You can get limited session information by using the 'omnirpt' function. I adivse that you review the syntax of this connamd in the Command lIne Interpreter Guide, available in your GUI by clicking Help -> Guides
The '-timeframe [start] [duration]' can be expresses as either in relative terms, such as 'go back 24 hours, and give the result of the subsequent 24 hours', or stated another way, give me what has happened in the last day, where it would be expressed as '-timeframe 24 24' or it may be expressed in terms of Absolute time
These reports may be configured in the Reporting context of the GUI. I would advise that you try running the reports from the command line first to see if they give you what you need
As I said, this gives limited session information. To get a full session report, you would need the session ID, and run the command
omnidb -session [session_id] -report Do not include the [ ] marks
omnidb -session 2013/12/23-1 -report
This output can be redirected to a file, but there is no provision to send it by e-mail