Try this monster -> http://en.wikipedia.org/wiki/Gigapixel_image
I just received an email with three pictures attached that was a total of 11.6 MP in size. That is ridiculous.
A dial-up modem would take an hour or so to download that email if the connection didn't fail.
I use MailWasher to preview my email. When I travel and use dial-up in remote areas, I just delete such large emails. Sometimes I reply to the sender suggesting they use the Powertoys picture resizer in Windows XP but all to often they have Vista and resizing a picture is not among their computer skills.
Bigger isn't always better in the hands of a novice.