K-9 Mail Issue: Outlook.com Duplicate Sent Email – Solved

Operating System
Android 4.4.2 “KitKat”

Device
LG Nexus 5

Email Service
Outlook.com (Microsoft)

Email Client
K-9 Mail (Connected via IMAP)

Problem
The send email function in K-9 Mail was working flawlessly, until for some reason it started saving two copies of each sent email in my Outlook.com Sent folder, and then syncing them back to the phone.

Solution
After researching the issue, I concluded that it had to be a syncing problem of some kind, so I set about finding a fix. Google came up with nothing useful, so I eventually found the solution on my own.

In K-9 Mail, go to Settings -> Account Settings -> Folders. You will see a list of the synced folders in K-9 Mail, and their counterparts on the Outlook.com server. Drafts should be linked to Drafts, Spam to Junk, Trash to Deleted and Sent to Sent. All looks correct, right? Except that it isn’t.

Linking the local Sent folder to the Sent folder on the Outlook.com server seems cause duplicate sent email to be created. If you set the local Sent folder’s linked status to -NONE-, the issue is fixed. A copy of the sent email is still saved in the Sent folder on the server, but there are no duplicates. Syncing works as before.

This solution may be applicable to other email services besides Outlook.com, provided that they allow the use of IMAP.

About
Use these instructions at your own risk
This document can be copied and edited according to the GNU General Public License (version 3 or newer). http://www.gnu.org/licenses/gpl.html

F-Droid: K-9 Mail App Review

Operating systems
Android 4.4, 4.1.2

Testing devices
Sony Xperia S (LT26i)
LG Nexus 5

F-Droid app review: K-9 Mail, a full-featured email client
K-9 Mail is an open source email client for Android, published under the Apache License version 2.0. It’s written in Java, and is available from F-Droid and Google Play among others. K-9 Mail supports the POP3 and IMAP protocols, including Push IMAP support. It also supports multiple accounts.

While I can verify that it does indeed support POP3 and IMAP, the Push IMAP for Microsoft’s Outlook.com email service remains nonfunctional for me. There is a bug report filed for it, and that comments there would suggest that other email services may also suffer from the same issue. That aside, the rest of the functionality is solid and working.

K-9 Mail features extensive customization options both to the appearance and functionality of the client, which I personally consider a major bonus over most other mobile email clients. The option to disable unnecessary features and tone down the UI to a more minimalistic approach is something I haven’t been able to find elsewhere.

I use the client with my Outlook.com email account (IMAP), and I can honestly say that it’s very easy and smooth to read your emails using K-9 Mail as opposed to the default Android email client, or even Google’s own Gmail client.

From my personal experience in the past year and a half, I can say that K-9 Mail is one of the best mobile email clients I’ve ever used. The fact that it’s open source and doesn’t have any ads certainly contributes to a trouble-free user experience. If you’re looking for a full-featured mobile email client for Android with extensive customization options, IMAP and POP3 support, then I would recommend checking out K-9 Mail.

References
K-9 Mail, Google Code (https://code.google.com/p/k9mail/)
K-9 Mail, Google Play (https://play.google.com/store/apps/details?id=com.fsck.k9)
K-9 Mail, F-Droid (https://f-droid.org/repository/browse/?fdfilter=k-9%20mail&fdid=com.fsck.k9)
Karvinen, Tero: Lessons 2013-11-21, Mobiilituotekehitys [Mobile Application Development] (http://terokarvinen.com/2013/aikataulu-%E2%80%93-mobiilituotekehitys-bus4tn008-3-syksylla-2013)

About
This document can be copied and edited according to the GNU General Public License (version 3 or newer). http://www.gnu.org/licenses/gpl.html
Based on a course by Tero Karvinen, http://www.iki.fi/karvinen