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Blue Mail vs. K-9 Mail vs. Gmail: The Best Email App Debate

On Android, there are plenty of easy to use, and highly rated email apps. If I had to decide between three, it’s between Blue Mail, K-9 Mail, and Gmail. Each of these three has their pros, cons, and reasons to use one over the other. All of them are free, so you don’t have anything to lose by trying one, but what does each one do best?

Related: How To Set Up Email on an Android Device

Gmail is simple, fast, and comes stock on almost every Android device. Blue Mail is an easy way to view all of your different email accounts all in one place. K-9 Mail excels with customization because of its open source potential. There isn’t a single bad app among the three, so let’s start pitting them against each other.

Our Ratings:

Blue Mail:  4.5 out of 5

Blue Mail is perfect if you’re looking for a custom experience, but don’t have much knowledge about modifying open source programs. The app gives you a hub where all of your email accounts are, and lets you switch between them at a moment’s notice. You get notifications for each, but setting the frequency and permissions is easy and fast.

K-9 Mail: 4.2 out of 5

K-9 Mail offers an almost staggering amount of customization, but only if you’re willing and able to dig deep inside of the experience. The app still offers useful email features filing, signatures, and multi-folder syncs, but not every part of the app is as user-friendly as other programs.

Gmail: 4 out of 5

What can I say about Gmail? It’s an above average email app that works when you need it to and hasn’t given me any problems since I first started using it. It doesn’t have any extra frills, but it isn’t bogged down by any battery hungry features either. Gmail is simple, effective, and does everything it can to provide a great Android email experience.

Google Play Ratings and Links:

Blue Mail:  4.7 out of 5

K-9 Mail: 4.3 out of 5

Gmail: 4.3 out of 5

Most Accessible Interface – Blue Mail

I was originally going to give this win to Gmail, but I remembered that for my first time using both apps, I understood how to use Blue Mail faster than the two other candidates. I understood BlueMail much faster than the other two apps because of the inbox setup.

blue inbox setup android email

By default, Blue Mail starts you with one unified inbox for all received email (that isn’t flagged as spam), while Gmail, and to a lesser degree K-9 Mail, split the inbox into different categories automatically.

gmail inbox setup android email

It only takes a minute to familiarize yourself with each app and configure your inboxes the way you want them, but Blue Mail struck a familiar chord with me immediately. Since all of the apps have similar inbox setup possibilities, Blue Mail’s interface wins because of a simple start and has labels for each setting that make sense.

Least Battery Hungry App – Gmail

This category isn’t even a close contest. Both BlueMail and K-9 Mail kill my battery unless I fiddle with their settings. Gmail on the other hand barely leaves a footprint by default, even if this changes when you tweak email synchronization settings.

Related: 5 Android Apps to Detect Battery Drain

As much as I love Blue Mail, there have been multiple times where I’ll see my battery drop from 80% to 60% in minutes, even while in standby. When I check to see what’s taking up all of my battery, nine times out of ten, it’s Blue Mail. This has gotten better with updates, but other users, and I, have had the same problems with K-9 Mail.

Related: How to Increase the Battery Life for Android Phones

Gmail is one email app that I trust not to snack on my battery when I leave my phone in standby, so it takes this category by a mile.

Most Customization Options – K-9 Mail and Blue Mail

Besides the fact that it’s open source, K-9 Mail has an overwhelming amount of ways to tweak and fiddle with your Android email. At the same time, Blue Mail has a great amount of customization built in that you can use across several different email accounts.

k9 mail folders android email

So while K-9 Mail has more customization to offer, Blue Mail is easier to customize for most Android users. This is down to how deeply you want to dive into your apps to change your email experience. If you enjoy taking apart and building up open source programs, then K-9 Mail is the clear winner here.

k9 open source android email

If you just want a custom experience without needing any extra work or knowledge on your part, Blue Mail is an easy choice. Gmail, as nice as it is, doesn’t have nearly as many options, even with all of its different inbox systems. Personally, I wish I had the knowledge to get as much use as possible out of K-9 Mail.

Easiest Email Conversion – Blue Mail

By conversion, I mean switching from one email service or app to another one. Since Blue Mail works with so many different existing inboxes and easily lets you switch between them, it wins this category.

blue mail conversion android email

If you think Gmail only supports other Gmail accounts, you’re wrong on that front. It supports Outlook and other email accounts, but only if you dig into your account settings and take advantage of it. On the other hand, the first thing you see in K-9 Mail is a message about a lack of support for certain accounts.

k9 mail warning android email

If you compare these two to Blue Mail, which opens up with a button selection for each kind of email account you want to use, it’s no contest. If you have more than one email address you want to consolidate into one app, or just switch apps quickly, Blue Mail is the best app for this.

Fastest Inbox / Folder Sync – K-9 Mail

Related: Android Add-Ons for K-9 Mail

How fast an inbox or a folder syncs determines how quickly you get a notification about new mail. If it’s important that you’re able to respond to your emails as fast as humanly possible, K-9 is the best app out of the three. K-9 fetches emails within seconds of them being sent, and is constantly scanning for new messages; it’s no wonder it’s a battery hog.

k9 mail sync android email

Blue Mail comes in at a close second while it munches on your battery almost just as quickly. That leaves Gmail as the slowest, but thankfully the most battery considerate of the three apps. If near instant access is what you need, leave it to K-9 mail to have your back.

Most Appealing Design – Blue Mail

This is the most subjective category on the list, so feel free to disagree with me. As far as looks go, I think Blue Mail has the most attractive design out of all three. It’s simple, yet refined, and most importantly of all, is easy on the eyes no matter how long you’re browsing and replying to emails.

blue mail design android email

Blue Mail’s design is similar to Gmail since it uses a lot of round objects and soft grays on top of another deep color. Blue of course pairs with Blue Mail, and red with Gmail. Where Blue Mail beats out Gmail is the design customization. If you don’t like how certain icons and aspects of your inbox look, then you can change them in just seconds.

gmail style android email

K-9 Mail features a blockier design than the other two that isn’t appealing to me, but other users will appreciate its appearance. Regarding being unique, K-9 mail is the winner, but overall, I prefer Blue Mail.

The Biggest Strengths and Weaknesses of Each App

From just looking at the ratings, and my own thoughts one each app, you’ll see that there’s a blue trend happening. However, just because I favor one email, app over the others doesn’t mean each doesn’t have their value. I’ve already picked my winner, but maybe a different email app suits your needs better.

Blue Mail is my favorite of the three, and my current email app, but what are the pros and cons that make it worth using, or worth passing? It’s easy to use, highly customizable, has an appealing design, and supports a multitude of email accounts, no matter the service you were using beforehand.

That all sounds amazing, and it is, but one of Blue Mail’s biggest weaknesses is how much it drains your battery. On nights that I don’t leave my phone charging, I’ll sometimes wake up and see that Blue Mail alone ate over 20% of my charge in standby. If you use Blue Mail, please keep your phone charged frequently.

K-9 Mail is an extremely capable app and is even better if you have the right toolset to use it to its full potential. It syncs incredibly quickly, with fast response times, letting you reply and send emails as quickly as possible in a matter of seconds.

The only real issue here is if you don’t have the toolset required, or the battery to support it, K-9 Mail isn’t as great as other email app options out there. If you don’t like fooling around with open source programs, there are better Android options out there.

k9 mail example android email

Gmail is an email app that almost every Android user has at least opened once. It’s simple but effective design is enough to keep a good chunk of those users using Gmail forever. For what it is, it works well and is incredibly light on your battery. If you’re worried about an email app syncing every few seconds and draining your phone, Gmail isn’t that app.

However, if you want any added features that come with those battery hungry apps, you won’t get them here. Aside from moving a few things around, Gmail doesn’t give its users much to customize or change, but at least you can use more than just Gmail accounts with the service.


Out of all three email apps, Blue Mail is my clear favorite and winner. Blue Mail offers a deep level of customization, is easily accessible with some different email accounts, and wraps all of its features into an attractive blue on the gray package. Ignoring the battery issues, it’s the perfect app for almost all Android email needs.

If you have a different, favorite Android email app that wasn’t on this list, feel free to leave a comment below; we appreciate your input!

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  1. One of the nicest features in Blue Mail is the Multi Edit mode. This allows you to select any number of files simultaneously. IMO: This the most important feature in an email program. Why this feature is not in gmail yet baffles me.

    1. That is a great feature. I recently came across BlueMail when I needed an email app on my Nexus 5x. It seems to work really well so far.

  2. I came across BlueMail a while back when I switched from the Gmail app. You absolutely hit the nail on the head, it’s a really slick way of handling all of my accounts without any major configuration mess. Cannot recommend enough!

  3. Gmail can’t configure to my company’s webmail. I forgot why. I gave up trying after finding out in various discussions that it is impossible. I was in a hurry and remembered K9. Didn’t know about Bluemail. I easily configured K9 to my webmail. However K9 way is currently a bit confusing. Its design is simple. Yet has lots of options. I have yet to take time and fiddle with it. Didn’t notice the battery drain problem though.

  4. Thank you for this comparison. I have gotten numerous suggestions for what app to try as my newest LG phone only came with Gmail. I need to monitor 3 emails hosted by godaddy and am searching for the best options. All 3 of these were recommended.

    I am curious if there is any update on the battery drainage issue with blue mail. I was dead set against gmail and ready to download blue mail until I ready your information here. Now I am back on the fence.

    Thank you

    1. Hi Miss Bonnie! According to reviews, Blue Mail is still very resource intensive, taking up a lot of RAM and quickly eating up battery life. I use Gmail to manage multiple accounts and find it very convenient!

      1. BlueMail actually has a setting you can use to make it moderately better on battery. If you go settings – account settings – tap any account – scroll down and open notifications, you can change the Instant push to a no-preview push, or to a slower fetch interval, which does adversely effect fetch speed, though if you’re expecting an email you can manually refresh. If you have a seldom-used account you could even set it to the max, 12 hours for automatic fetches.

  5. I am looking to stop using the Yahoo mail app on my android because it drains my battery so much. Does anyone know if bluemail would be an improvement over yahoo mail in terms of battery life? Thank you.

    1. Hi Steph! In the past we’ve heard that Blue Mail isn’t easy on the battery, but they’ve recently taken steps to improve the battery life. It’s definitely worth giving it a try.

  6. Great review of k-9 and Blue mail – I didn’t even know Gmail might handle my 5 accounts. Do any of these offer the option to store “sent” mail in another folder/label (inbox instead of Sent)?

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