There is no trick, Lewanda. The attachments using the file manager sometimes take a bit to load, and that's possibly why people can't see them at first. Also, the file manager has issue with spaces (in file names), I believe, so that could be another reason people couldn't see the images. And no, there is no way to post zip files without uploading them.
The bigger the picture in the attachment, the longer it takes to load. It will not be instant.
If you are using the file manager to upload your zip files, it shouldn't be using any of your personal web server space.
Edited by Xay (07/11/09 11:02 PM)
Edit Reason: additional info