You do need to update the AttachmentPosition property. I found that it had to be within the boundaries of the body text. The way I found around this was to add some spaces to the end of the body text (enough to cater for all attachments) and place the attachments in these spaces.

If you use attachment position 1, it will place the attachment before the first character of your text. Position 2 will place between characters 1 and 2. And so on.

Also, you don't need to update the AttachmentCount property, just set AttachmentIndex to equal AttachmentCount and the count will be automatically updated.

>But I found the FAQ, and it says you HAVE TO update the AttachmentPosition property, check out the link.