I'm sorry to hear that.
I just thought though. Since your not running from Microsoft Outlook Express or something to get your e-mail and are just using an online web server, your ISP probably wouldn't have it anyway.
The only people I can assume would have it would be them, on there main servers, even if you did put it on trash. I'd assume they'd have a tempory delete on there main servers, rather than just your inbox.
Though you need to recover 6 months?! I don't know if they'd have stored that much...
One thing you could have tried since it was webbased was to keep pressing back to see if it would bring back the messages, like to take back what you did...though you've probably closed it off by now
I'm sorry I can't help any more than I am
I got this from the site...and it doesn't seem good
"Note: It is important to know that when you delete your mail from your Inbox Folder, you are actually moving it to your Trash Folder. You can still view the messages in your Trash Folder until it is deleted. Once the emails are deleted from your Trash Folder, it is permanently deleted and you will not be able to retrieve it."
What exactly do the documents contain you need to retrieve? Is there another way you could proove it? Maybe asking the person who sent the e-mail to try and recover them from there sent messages and send them back to you...