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Delta Chat, caratteristiche principali
for Android
for iPhone
for Linux, macOS and Linux
Open source
End-to-end encryption
free
messaging app that uses the email protocol
you can send audio, video, photos and current location
There is no central Delta Chat server, you use your own email provider
security audits
For those who haven't noticed yet, we recently inaugurated a new section dedicated to the world of reviews where we plan to insert individual reviews of the applications and projects that we find most interesting. It is also divided into categories which for now are: Browsers, messaging, operating systems, search engine hey cloud storage. The idea is to be able to best express the strengths and weaknesses of each individual project without tying them to a few lines of explanation within the various articles.
Some old articles have been collected within this new section and others like this one on Delta Chat and for example the one above GrapheneOS they were created specifically. In the hope that it is to your liking, we will continue to propose, in addition to general alternatives, also individual reviews after having tested the various applications.
Delta Chat, emails as WhatsApp messages
We wanted to talk about Delta Chat because it seems like a very interesting project to us but above all because we think that the work that has been done is nothing short of crazy. Explained in simple words: Delta Chat turns emails into a chat-style message. And he does it so well that it almost seems like magic!
One of the advantages of this idea is that there is no central server that manages or sorts the messages that pass over Delta Chat. But let's see in practice how to start a conversation and how it all works.
Which email provider to use
First you need an email address that has IMAP access. Almost everyone allows it but we have to exclude some of our acquaintances such as Proton Mail And Tutanota for example that, for encryption reasons, they do not allow access to this protocol (Proton Mail allows it only in the paid version and only through the their bridge for desktop).
Exists this list which allows you to know in detail which providers it works on, which servers require a little preparation/setting and which ones run smoothly without needing to touch anything. It also exists this other table where many more features are marked for each individual provider.
Here, we tried it with Infomaniak, one of ours old acquaintance (as well as our current one Hosting for the site). They also offer free 20GB email with IMAP access, in case you want to give it a try too.
So will I see all my conversations in my inbox?
No, there is a risk. However this should be prevented by programs (FairEmail) and from intelligent providers (Infomaniak) which will put the DeltaChat folder outside of your normal inbox and you will essentially notice nothing.
However, the general advice, especially for a novice, is to create an email specifically to be used only with Delta Chat and thus cut the corner without risking finding yourself with constant notifications and unwanted messages in your main inbox.
Add your email account
Now all you need to do is know your provider's IMAP settings. In the link we gave you before, that is This, by clicking on the name of the provider you will arrive on a page where at the bottom you will find the wording Technical specs 1. By clicking on Technical specs you will find the technical specifications for that provider, for example these they are the ones for Infomaniak.
Now download Delta Chat, enter your username and password and if you want, immediately press the ✔. If a autoconfig in the domain then it will do everything automatically, otherwise press on Advanced and enter what is asked of you, that is:
- Arriving
- IMAP username (generally your entire username, including domain);
- IMAP server (in the case of Infomaniak it is mail.infomaniak.com);
- IMAP port (in the case of Infomaniak it is 993).
- Output
- SMTP username (as above, usually your full username);
- SMTP password (your password);
- SMTP server (in the case of Infomaniak it is mail.infomaniak.com);
- SMTP port (for Infomaniak it is 465).
You can leave the rest unchanged. If you have entered all the right data in a few seconds you will be taken to the homepage of the application which, as you will have noticed, it looks like any messaging app.
Start using Delta Chat
Now you will have noticed that you will have two chats already active: one is local and is automatically generated by the device based on any updates present on the application. The other is Saved Messages: as well as on Telegram, you can create and/or forward messages or notes (written and vocal) that they will be encrypted end-to-end on the server.
Now that we have said this, reread it a second time to better understand its potential: you can save a photo, a voice or written note using the space in your email inbox and without your provider being able to read it in any way.
Cryptography
In this regard, the chats on Delta Chat as you may have easily guessed are encrypted end-to-end using Autocrypt 2. Since it's not enough to say I use Autocrypt to say that things are done well they have also released multiple audits (to date three) which confirm their correct implementation. The third, and last, is at the end of March 2023 3.
Chat on Delta Chat
Therefore, as regards the messages saved in the private folder, as you may have guessed, they are quite safe without you doing anything else. As for messages exchanged with other people, the messages will only be encrypted if they use them Delta Chat (or another Autocrypt compatible mail app, here is a list), if you send a message to any other email address the message will reach that person in plain text (and it will also be saved in clear text on your provider's server). So you can somehow chat even with those who don't use Delta Chat, but remember that conversations they will not be end-to-end encrypted.
So it can also be used, if you like, as a simple mail application to read or write emails.
Add a person on Delta Chat
The easiest way to add a person on Delta Chat is the use of the QR code: just send your QR code to the person you want to chat with Delta Chat and she can add to it. Once you have exchanged the encryption keys, it is a semi-automatic process. Don't worry, you can chat as if you were on any messaging application.
The difference is that every time you press send you are actually sending an end-to-end encrypted email to the recipient and every time this person replies to you, an end-to-end encrypted email will be generated and therefore unreadable for your provider and for anyone else.
The thing that impressed us most is that it really looks like a messaging application with tons of options. In addition to sending a simple message, it is possible to:
- send a photo taken directly from your camera and in general any file present on your gallery including video, photo And audio;
- send the many hated voice messages;
- send your position (can be activated in advanced settings). This function is experimental and works like this: activate the location for a certain number of minutes and every message you write during this period will be automatically geolocalized and visible on the map. Each message will appear on the map as a dot with the message itself written on it.
Audio will be heard as audio, videos will be seen as video, photos as photos and so on. You won't even remember that you are using email protocols.
The groups
Groups also exist on Delta Chat! Therefore, it is not only possible to talk to one person but also to a group of people. There are two types of groups possible: one normal and the other verified. In the first case, encryption may not be present based on the users present, whereas in verified groups each member is verified with a second factor by the other members and messages will always be end-to-end encrypted.
A group normal it is a bit the equivalent of the good old mailing lists and could be a very interesting solution for various companies that do not want (and should not) rely on central servers with groups on Whatsapp, Telegram or Signal.
There already exists an Italian group that you can follow on various channels, you can find all the instructions at this address. The Alternatives is not present as a group on Delta Chat because it seems a bit redundant to us (we already have many systems that don't even require email as Feddit). Let us know in case you are interested because, as always, you can think about it.
Calls and video calls
As you have probably already imagined, there are no native video calls since these would not be possible through the protocols used for emails. To overcome this, Delta Chat allows you to exploit servers Jitsi or BigBlueButton. To use them, they must first be enabled in the advanced settings by entering your preferred server. For example, if you want to use the main Jitsi Meet server you can enter: https://meet.jit.si/$ROOM to allow you to create a different room each time (the $ROOM variable is used precisely for this). Another server you can try is https://kmeet.infomaniak.com/$ROOM.
Webxdc bots and apps
Delta Chat offers some very interesting features such as the possibility of using and creating bots that can do various automatic things. Here, for example, you will find a list of public bots and free available to anyone.
Another notable feature is the webxdc apps, for which they also got funding from the program Next Generation Internet 4. They are essentially web apps that can be downloaded for free from their site and which allow you to collaborate or play with another person directly on Delta Chat 5.
The strengths and weaknesses
The application therefore, but above all the idea and its implementation, seem almost perfect to us. The advantages are many and are also listed in their FAQ 6, the most obvious are the fact that they are somewhat independent and that there is no single central server but a system that has already been tested for decades is used. You won't have to share your address book with third parties and anyone can talk to you on Delta Chat, even those who don't have Delta Chat!
One of the problems of Delta Chat is the fact that somewhere space, understood as data to be maintained, could become a problem. So either you automatically delete the messages from the server (there is the option to do so) or you use it consistently and with many people you will take up all the space in your email inbox in a few months/year. However, you can export all messages, contacts, chats and settings to another device and then import it later. Some providers, such as Infomaniak, promise unlimited storage space in their paid emails (a few euros per month).
Another problem is related to metadata: email was not really designed to be a totally secure or anonymous system. Your provider will know that you sent a message to email 'xxx' at that moment and your recipient's provider will know the same thing. Each mail server will be able to inspect the various To/CC headers (for unverified groups) and therefore will be able to know who is part of a group. The IP address from which you write will be exposed to the email provider who will therefore be able to know that the specific IP address wrote to the email inbox at 'xxx'. It's nothing particularly alarming or striking and you've certainly seen worse around (Telegram chats are not end-to-end encrypted by default while audio and video calls are, for example 7). However, it is always good to know and understand if it is the solution for you based on yours Threat Model, i.e. based on your threat model.
Many other headers, such as the subject, are protected by the End-to-end encryption 8.
The limit of emails sent
Another possible flaw, especially when we talk about free providers, is the limit on sending emails per minute/hour/day. Unfortunately, almost all providers have a limit but very few display it clearly. ServerMX, for example, has clear and very specific conditions. In this way a person can decide independently whether it is the right provider or not. Others, however, have the limit but do not declare it openly (or if they do it is hidden somewhere). This is also why he was born this site to understand which provider to use.
We know for example that Disroot has very specific limits but if you contact them to tell them that you want to use Delta Chat they are generally willing to raise the limit.
Infomaniak, which we talked about in this article, should not have a limit on emails sent in the paid version.
In general, the rate limit can be a problem if groups are used a lot because often for providers what matters is not so much the actual number of emails sent but how many people the same email is sent to.
Who is Delta Chat funded by?
It's a project Open source and free, does not earn through advertising or anything else but only through donations. Throughout their history they have received many funds from private foundations or public bodies 9.
Fork by Delta Chat
Since Delta Chat is free software, there are also some Fork, that is, modified versions of the application. One of the most important and most stable is certainly DeltaLab available on Android via IzzyOnDroid or via APK. It has several extra features compared to Delta Chat including Markdown support, support for animated Telegram stickers, the ability to delete all messages in a chat, a default video chat server and much more.
Where to download Delta Chat
Here are all the links to download and use this application.
• • • • • •- example Infomaniak[↩]
- What standards are used for the End-to-end encryption?[↩]
- Good news from security audits, past and present[↩]
- How is the development of Delta Chat financed?[↩]
- Sharing web apps in a chat[↩]
- What are the advantages of Delta Chat over other messengers?[↩]
- End-to-End Encryption FAQ[↩]
- Protected Headers for Cryptographic E-mail[↩]
- How are Delta Chat developments funded?[↩]
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