I've done some tests with attachments and PureSmtp and PurePop3 both seem to append extra an extra $0D0A to the end of the file (each adds 2 bytes).
The file was a text file consisting of 'blah blah blah!' (15 bytes, no CR)
PureSMTP made it 17 bytes long (verified with TheBat and Outlook) and PurePop3 made it 19 bytes long (verified with a direct PurePOP3_SaveAttachementsToFile command)
Also, during the course of the 'testing', I think I may have found an attachment type that is not compatible (from TheBat), here is a dump of the raw message:
+OK 1213 octets follow.
Received: from [192.168.0.11] (xxxx.dsl.xx.co.uk [xxx])
by spunkyxxxxxxxxamhost.com (Postfix) with ESMTP id 37444433371DC
for <email@example.com>; Tue, 16 Jan 2007 13:44:49 -0800 (PST)
Date: Tue, 16 Jan 2007 21:44:56 +0000
From: User Test at ezxretary <firstname.lastname@example.org>
X-Mailer: The Bat! (v3.95.6) Professional
X-Priority: 3 (Normal)
Content-Type: text/plain; charset=us-ascii
name="this is a test.txt"
filename="this is a test.txt"
I've changed any identifying marks to stop my email from being spammed!
When PurePop3 saves the attachment, it ends up as:
It should be:
blah blah blah!
Maybe its the extra two '--' that TheBat puts at the end of an attachment boundary string?