The latest public beta of Iris email client introduces an Outgoing Messages folder. The emails you write are 1st stored in a local folder on disk, then uploaded to Drafts on your IMAP server, sent via SMTP and either deleted or moved to Sent folder on success, depending on whether the server automatically uploads sent messages to Sent folder or not.
This version also introduces 2 new main window UI layouts, the ability to fall back to Scintilla instead of OWB for viewing and editing (for systems with constrained ram) and many other fixes. See the README file for the complete list of changes.
The archive can be downloaded from tunkki