1gravity LLC

Welcome to 1gravity

Another Battery Test

Here's another test result.

While K-@ Mail and K-9 Mail were configured with 10 email accounts each, AquaMail and MailDroid had to synchronize but a single email account (Yahoo! in MailDroid's case, one IMAP Push account in the case of AquaMail). Stay tuned for the new version to come...

K-@ Mail 1.3 Screenshot

K-@ Mail 1.5.6 / 1.5.7

While K-@ Mail 1.56 focuses on reducing the duration and number of wake locks (used to keep the device awake while the app synchronizes mails), K-@ Mail brings a completely redesigned IMAP IDLE implementation (push email). While the "old" IMAP IDLE implementation was performing well enough if the network connection was stable (strong WLAN or mobile network without switching between networks), it didn't do so well when the network connection changed a lot (on the move), the signal was weak and some other "non-ideal" network situations. This could in some cases lead to heavy battery drain. The new implementation should be able to cope with these situations much better.

While we usually don't compare K-@ Mail publicly to other email clients, it's important in this case to show the impact these changes can have on battery use, so we compared K-@ Mail 1.5.7 with K-9 Mail 4.903 which used more or less the same mail synchronization code as K-@ Mail before version 1.5.6. We analyzed the following four situations:

  1. Strong WLAN - arbitrary mobile network
  2. No WLAN - weak mobile network
  3. WLAN not authenticated - arbitrary mobile network
  4. No connection at all

The tests were performed with an identical setup for K-@ Mail and K-9 Mail: three Gmail accounts, three 1gravity accounts, three IMAP accounts (all nine accounts using IMAP IDLE and no polling), 1 Hotmail + 1 Yahoo! account (no IMAP IDLE but polling every 15 minutes).

Here are the results: 

Strong WLAN - arbitrary mobile network

In this scenario the device is connected to a stable WLAN and while it's also connected to a mobile network that network connection doesn't matter because all data transfer goes through the WLAN.

K-@ Mail 1.3 Screenshot

K-@ Mail 1.3 Screenshot

As expected there are no issues with wake locks and battery lifetime in this scenario.

No WLAN - weak mobile network

In this scenario the device is connected to a weak mobile network only. "Weak" means it might lose the connection from time to time or it might switch between 3g and 4g occasionally depending on the signal strength of the network. With each network change the IMAP IDLE connection has to be re-established too and that means waking up the device and using the radio.

K-@ Mail 1.3 Screenshot

K-@ Mail 1.3 Screenshot

As we can see K-@ Mail outperforms K-9 Mail when it comes to the duration of the wake locks by a factor of 3 and used a little over a 3rd of the battery K-9 Mail used.

WLAN not authenticated - arbitrary mobile network

When you're on the move in a city there are a lot of "open" WLANs your device might connect to without you even knowing. Most of them aren't really open but require to pay using a web authentication (and payment) mechanism. Should your device connect to one of these WLANs then it's theoretically connected to the "Internet" but the connection ends with the operator of that network. Email clients will find that the device is connected but they won't be able to connect to the email provider. Since the goal of each email client is to reliably synchronize emails they will retry after they fail the first time. And then try again, and again and again. Depending on how sophisticated that retry implementation is, your battery might get a really hard hit in this scenario. But let's see the numbers:

K-@ Mail 1.3 Screenshot

K-@ Mail 1.3 Screenshot

K-@ Mail 1.3 Screenshot

While K-9 Mail kept the device awake for more than half the time it was on battery (8:31 hours), it took K-@ Mail not even 2 minutes to "realize" there's no point in retrieving any emails. The battery statistics in impressive too. 28% of the used battery was used by K-9 while K-@ Mail is off the chart (in a good sense), it doesn't even appear on the list of apps using battery.

It has to be noted that both apps automatically synchronized all changes for the 11 mail boxes that were missed during the 8:31 hours downtime without issues once the device got a "real" connection.

No connection at all

If not handled gracefully this situation could lead to battery drain too but good news for both tested email clients. None of them woke the device unnecessarily and used "no" battery, at least not that it would show in the statistics.

K-@ Mail 1.3 Screenshot

K-@ Mail 1.3 Screenshot


K-@ Mail 1.56 has been released already while K-@ Mail 1.5.7 will be released shortly. Stay tuned.

K-@ Mail V1.40

K-@ Mail V1.40 has been released!

It brings numerous enhancements but the high-light is certainly the new message composition with the rich text editor.

K-@ Mail 1.3 Screenshot


Here's the complete list of changes:

  • Completely redesigned message composition screen with rich-text editor for message, quote and signature.
  • When forwarded and replied to, messages are now completely downloaded to include all text and attachments.
  • Added pull-to-refresh in account, folder and message lists analogous Gmail.
  • Pull-to-load-more in message list has been replaced by a "Load more" footer button.
  • Added support for Apex Launcher unread counts on launcher icon.
  • Added support for Nova Launcher (Tesla Unread) unread counts on launcher icon.
  • Added print function based on the new Android 4.4 native platform support for printing (Android 4.4 / KitKat only).
  • New function to empty all trash and compact all accounts (Account screen, overflow menu).
  • Volume key navigation in message list and message view (global settings, default is disabled).
  • Copy/move for messages in the Combined Inbox is possible now provided the messages belong to the same email account.
  • New setting to enable/disable contact pictures for notifications.
  • New setting to force auto-encryption for a message (account settings - cryptology).
  • Saved images (attachments) are now added to the device's media library.
  • The upgraded free version now changes its name to K-@ Mail Pro and uses the Pro icon (yellow).
  • Messages and accounts sections can now be collapsed/expanded.
  • The install order of APG and K-@ Mail doesn't matter any more. They can be installed in any order.
  • K-@ Mail would not accept certificates in some cases.
  • TLS is now STARTTLS, SSL is now SSL/TLS.
  • Performance improvements when displaying contact pictures and attachment thumbnails.
  • Much improved attachment / inline attachment handling (several issues).
  • Added Latvian translation (thanks to Raimonds Aboms).
  • Added support for Android 4.4 and fixed a couple of KitKat related issues.
  • More stable notification implementation.
  • Countless bug fixes and minor improvements.

K-@ Mail V1.30

K-@ Mail V1.30 has just been released.

This release is focusing on performance, stability and reliability but also includes numerous features users have asked for:


  • The new integrated file explorer allows attaching multiple files at a time
  • Multi-window support for certain Samsung devices (Galaxy Note II, Galaxy Note 10.1 ...)
  • Notification with preview of messages & reply button for Android>=4.1 (Jelly Bean)
  • Split-screen views can now be enabled/disabled for all devices and support now horizontal and vertical split
  • Calendar attachments (Outlook invitations) can now be opened
  • Configurable colors for the top and bottom action bar
  • The recipient of a mail is hidden in the message lists to free up screen real estate (exception: Sent folder)
  • The star button can be hidden from the message list
  • Long subjects are wrapped onto multiple lines in the message view
  • Improved printing support. The share function allows now to either share as text or as HTML. Some printing apps work better with one or the other option (CloudPrint with text, PrintHand with HTML)
  • The combined inbox and important messages are now supported by the unread widget
  • The account navigation (account drop down) shows the number of unread and total messages
  • Message list shows sender first then subject
  • The preview for attachments in the attachment spinner shows now an app icon for known types or thumbnails where possible
  • Inlined attachments aren't shown in the attachment spinner any longer (e.g. embedded images)
  • Images can be zoomed out completely now
  • Complete Italian translation (thanks to Salvatore Savastano)
  • Change log is shown once when app starts
  • Countless small improvements and bug fixes

K-@ Mail 1.3 Screenshot

This release is an important one not because it brings many new functions but because it brings speed and reliability and lays the foundation for all that is to come.

Much of K-@ Mail's underlying structure has been rebuilt and is now ready for the features we plan to implement in the next few month. Please stay tuned.