carrierwave

https://github.com/carrierwaveuploader/carrierwave

Ruby

Classier solution for file uploads for Rails, Sinatra and other Ruby web frameworks

Mail::Message#skip_deletion

Skips the deletion of this message. All other messages
flagged for delete still will be deleted at session close (i.e. when
#find exits). Only has an effect if you're using #find_and_delete
or #find with :delete_after_find set to true.

Source | Google | Stack overflow

Edit

git clone [email protected]:carrierwaveuploader/carrierwave.git

cd carrierwave

open

Contribute

# Make a new branch

git checkout -b -your-name--update-docs-Mail--Message-skip_deletion-for-pr

# Commit to git

git add git commit -m "better docs for Mail::Message#skip_deletion"

# Open pull request

gem install hub # on a mac you can `brew install hub`

hub fork

git push <your name> -your-name--update-docs-Mail--Message-skip_deletion-for-pr

hub pull-request

# Celebrate!