@Winter blue tardis🇧🇬🇭🇺 @Jayson Smith @Nick Giannak III The 25 port requirement is for self hosting #chatmail relay not for using the app. There are apps for other platforms such as deltachat for IOS, deltachat or arcanechat for android.
As for the deltachat-desktop app interface, unfortunatelly it's an electron app. However it's best used with the screen reader switched into focus mode.
I'll try to give you a bit of overview explaining how I am using it.
When I launch deltachat-desktop the focus is placed into a search field. If you alt+tab from its window and return back the focus will move to the chat input area if you have active conversation.
Regardless of which of these is in focus use tab and shift+tab to navigate at this point.
So I'll use the search field as a starting point as if you have no conversations this is the element you will land on after creating or importing your account from the backup.
Tabbing away from the search field you will land on the Scan QR code button. You can activate it to share your code for others to scan or to scan a code from someone else. Also we are all blind here in this conversation so I guess we won't be scanning QR codes, we'll copy and paste invite links that is also supported here. So the QR code dialog has two tabs QR invite code and Scan QR code. These are exposed as buttons to screen readers. If you activate one of these buttons the content in this dialog window changes. If you would like to join the chat you will press Scan QR code here and you will find the Paste button.
I assume QR code or invite links handling is now a bit clearer so I'll continue describing the main window.
When using tab to navigate pressing the tab key while the Scan QR button on the main window is in focus, you will land in the list of conversations. You can use up and down arrow key to navigate, enter key to activate here. Unfortunatelly the items are again exposed as buttons so it might be a bit embarrasing at first.
If you continue navigating with the tab key from the list of conversations you will land on the new conversation button.
If you continue with the tab key you will move from the new conversation button into the active conversation window. The conversation name is presented. Activating the button named after the active conversation will open a dialog window with user profile of your chat partner or profile of a group chat if the active conversation is a group chat indeed. In the profile window you can see last seen info of the chat partner, their signature, their chat handle, a button for sending them a message that is mainly usefull when you are looking at a profile of a group member, and an ability to share the contact with other contacts. There is a profile menu button that displays a context sensitive menu with more actions such as setting your own local display name for the contact.
I'm now done explaining the profile window and imagine we are back in the active conversation view focused on the chat name button.
Using tab key to navigate from here lands on the tabs changing the main conversation content. You can use these to change from conversation to the media.
Then there is a main menu button. In fact it includes conversation specific menu entries such as search in chat, dissapearing messages and others.
Moving forward with the tab key from the main menu button you will land on the message list of the active conversation. Use up and down arrow to navigate here to read the messages. And use applications key or shift+F10 to open a context menu for the selected message. Text messages have no other content but audio messages, messages with reactions or other attachments might have other focusable elements in the tab order. I think this part is pretty self explanatory once you manage to start chatting. One thing other messengers don't have is shared apps. Apps can be posted to the chat and message with the app will have a button to start the app that will then open in a new window. There are various apps made for deltachat and other webxdc capable messengers, such as the shopping list, simple group collaborative editor and similar. I am looking to the future when more screen reader users will adopt this and we can bring some of the fun things we liked to enjoy back in the days on IRC such as playing quiz or card games in the chat. This might be a nice platform for allowing this.
Then there is an attachment button, visually it's to the left of the chat input area, then chat input area it-self, smileys and record voice messages button.
After the record voice message button you will wrap to the top, of the application window landing on the profile chooser. This part needs a bit of a11y love as the profile names are not exposed to screen readers. These have role tab and you can use up and down arrow keys to navigate here. The last item in this list is a create profile button.
Yes, you can have multiple chat profiles if you like. And it's really damn easy to create a new deltachat profile. The most valuable thing on your profile is the list of contacts as you are verified criptographically. Loosing the empty profile is not a problem as you can create a new one whenever you like.
The final destination of this walkthrough through the deltachat-desktop main window is the settings button.

Huh, this turned to be a looong post. I believe it clears a few things up for you.

Thinking more about it perhaps I should report some of the little things such as avoid using button roles for the list items, consider using roving tab index for the tabs so only one of them is focusable at a time to get rid of a bit of confusion to the @Delta Chat github issues.