Yes, but it's a bit of work. First, when you delete a message, it's only made invisible. By changing the first character of the filename to a special character, the operating system counts the space on the disk as empty, but the data is still there. Programs like Norton Utilities can still read the data. There are some programs that overwrite the data making it irretrievable.
Then, every email travelling through the Internet leaves a trace in the servers it passes through. It is possible to go to those servers and get that information, tracing it back to the originator. Still, it's a bit of work, most likely can't be done without a warrant, and not the sort of thing that casual people would try to do.
For an interesting look at headers, open your e-mail program and view the Internet Headers. Here's an example:
X-Apparently-To: hbrt@verizon.net via 68.142.206.181; Thu, 26 Oct 2006 11:22:31 -0700
X-Originating-IP: [206.46.252.46]
Authentication-Results: mta107.vzn.mail.mud.yahoo.com
from=verizon.net; domainkeys=neutral (no sig)
Received: from 72.70.196.228 (EHLO vms046pub.verizon.net) (206.46.252.46)
by mta107.vzn.mail.mud.yahoo.com with SMTP; Thu, 26 Oct 2006 11:22:31 -0700
Received: from Laptop ([68.237.140.210])
by vms046.mailsrvcs.net (Sun Java System Messaging Server 6.2-4.02 (built Sep
9 2005)) with ESMTPA id <0J7R006GR9P30HDF@vms046.mailsrvcs.net> for
deirdrehbrt@verizon.net (ORCPT deirdrehbrt@verizon.net); Thu,
26 Oct 2006 13:22:25 -0500 (CDT)
Date: Thu, 26 Oct 2006 14:22:13 -0400
From: "Chandler"
Subject: All about me...Just for fun
To: "Timoth"
Message-id: <008301c6f92b$aa9836d0$2c01a8c0@Laptop>
MIME-version: 1.0
X-MIMEOLE: Produced By Microsoft MimeOLE V6.00.2900.2962
X-Mailer: Microsoft Outlook Express 6.00.2900.2869
Content-type: multipart/alternative;
boundary="----=_NextPart_000_0080_01C6F90A.21DE3E00"
X-Priority: 3
X-MSMail-priority: Normal
References: <92c357ae3468db33a39355ff0eddeee9@comcast.net>
X-NAS-BWL: Found match for 'chandler@verizon.net' on the allowed list (5 addresses, 0 domains)
X-NAS-Classification: 0
X-NAS-MessageID: 116
X-NAS-Validation: {C420940D-6840-4048-A182-50B4D80E27A7}
I changed the emails to preserve privacy, but you can see that each server the message went through left its IP Address. Each of those servers has documentation of this message as well. The details are kept for vairous lengths of time, but they are traceable for a while.