Is there web app that can open
.eml attachments properly?
(Updated) I did a search and found a service by a company named Encryptomatic. The web page lets you specify an .eml file (or other file formats such as .msg) from your computer. It will then render the contents of the file.
A note from a legal/privacy perspective: When you specify a file, you are essentially giving the service a copy of your file. I assume they are reading the copy and then deleting it, but I have no knowledge or connection with the company or the service.
This question is old but I'll chime in anyway.
You shouldn't have to rely on webmail services for this task (I'm talking from a privacy perspective). I would suggest downloading a free e-mail client and open the .eml file locally.
I am using Mozilla's Thunderbird which is free, and opens .eml files excellently (attachments rendered properly as files and all). From that point, you can choose what to do with your e-mail: extract contents, download attachments, forward etc.