I need my .net program to send rich emails (usually containing table data, around 20 columns x 10 rows) using the user's mail infrastructure, allowing him to review/edit the mail before sending it, and storing the mail in his 'sent items' folder.

1. mailto: seems the obvious choice, but unfortunately, it doesn't support neither attachments nor html bodies. It seems some clients support some extra features (e.g. Outlook 97 used to support a &Attach tag, but this is not the case for more recent versions).

2. I could use mailto and try to format the text body to look nice (using tabs, etc), but this isn't really elegant and wouldn't support huge data.

3. using automation seems a very huge task, as I would need to automate dozens of clients (4 or 5 versions of outlook, lotusnotes, thunderbid, etc.) ... This would be a huge task and it's not really my core business ...

4. I could send emails through code and write my own mail form to let the user edit the mail, but this would have a lot of drawbacks :

   • the user would need to manually configure the mail server settings
   • he wouldn't have access to his contact directory
   • the mail wouldn't be sent in his sent items folder

This seems a quite common issue, but I haven't found any satisfying solution yet ; does someone knows of a library supporting this (ie containing automation logic for most mainstream email clients?). Or an alternative to mailto ?