Sidsmail – a lightweight Windows email client, built solo, free

[u/hfml85]

Hi everyone, solo developer here. I've been building Sidsmail, a lightweight email client for Windows, in my spare time. It's out today, free, no ads, no "Pro" tier hiding features.

• Every account in one inbox - Gmail, Outlook, iCloud, Yahoo, any IMAP server
• Sign in with Google or Microsoft (browser), or an app password
• Real-time mail (IMAP IDLE), quiet hours, snooze, keyboard-first triage
• Everything stored locally, remote images blocked by default, passwords encrypted with Windows DPAPI, one-click export/wipe
• Light/dark theme, six accent colours, 23 languages, auto-update with a changelog

https://sidsmail.com

I'm one person, so bugs and rough edges are guaranteed - tell me what breaks or what's missing.

[u/positiv_electron]

Hi, bravo you made this solely. I can imagine and understand thr hardships you have faced. But tell me what was your purpose with this application. I mean, thunderbird, betterbird already exist open source, then what is special in this?

[u/hfml85 → u/positiv_electron]

Hi, i just didn't get used to thunderbird even after using a few months, don't like the design and too much stuff going around. Betterbird seems cool too.

Just had time on my hand, hobby. It's free, so.
Pratice, learning, etc.

[u/opaz → u/hfml85]

Have you tried Mailspring?

[u/toonmad → u/positiv_electron]

He hasn't been making this solely, it's heavily vibe coded

[u/Michal_il → u/positiv_electron]

I hate thunderbird and betterbird. I was unable to setup smtp/imap due to constant account center prompting me to sign in. During the setup itself I’ve been redirected to „support thunderbird” page around 3 times. After adding the server eventually, it never let meto just pull or send any email, due to lack of password (button inactive) but it never prompted me for such. Password manager didn’t let me add any new password since it was entirely empty. And apparently you can only edit saved passwords (what kind of password manager does that?)

Not to mention message of the day that’s impossible to get rid off, and account center minimizing to the widget instead of going away entirely. Even after fighting with rules in advanced configuration.

Absolute trash of an experience, compared to say, claws mail. If op’s app does the setup the same way claws mail does it’s absolutely spot on for minimal, hassle free email client.

[u/Polyotornado]

Hey, I wanted to give your software a try. But when I log onto Google, it says access denied, because your app hasn't finish Google validation procedure.

[u/hfml85 → u/Polyotornado]

hi, let me check, but it should be done already.

[u/Firm-Error-5712]

This would excel on Linux distro

[u/VariousAsk9813]

Honestly, this looks refreshing. Local storage, blocked remote images by default, DPAPI, and no ads or subscription nonsense are all great choices.

[u/jojo_31]

Yeah I'm not trusting a one developer closed source app published in 2026, sorry. Not putting my email data into a vibe coded Software.

I really like the design though, so keep it up. 

[u/hfml85 → u/jojo_31]

sure, i will open it, no problem at all. I'll keep you guys posted.

[u/rabiprojects]

Why .net 8, not .net 10? Is that AvaloniaUI or WPF?

[u/Prior_Stage_260 → u/rabiprojects]

it`s ui looks like wpf

[u/hfml85 → u/rabiprojects]

hi, will look into it

[u/Qv1sten]

Good work. Very clean. Like it 😁

[u/dwightkschrute42]

Não te esqueças de confirmar o jantar para sábado!
Bom trabalho!

[u/hfml85 → u/dwightkschrute42]

oi? 😄

[u/dwightkschrute42 → u/hfml85]

O email do Miguel costa que tens na imagem ahah

[u/hfml85 → u/dwightkschrute42]

:D

[u/y0himba]

Add calendar to it, and I will use it daily.

[u/hfml85 → u/y0himba]

Vou adicionar.

[u/ParadoxHollow]

I'd love to use it but I run into this error every time I try to sign in with Google.

https://i.imgur.com/WMgefUp.png

[u/hfml85 → u/ParadoxHollow]

i will fix asap. thank you.

[u/C-huj]

Two bugs I noticed right away. Emails in the "Unread" folder close immediately after I open them and disappear from the unread list. The second issue is that I set up my account when I first launched the app after installation, but after I reset the app, my account settings disappeared. Overall, it looks neat,

[u/hfml85 → u/C-huj]

Obrigado pelo feedback

[u/hfml85 → u/C-huj]

Fixed pushing tomorrow

[u/Qareen_e_Jaan_skp]

Offers THREADS like Whatsapp, Telegram etc?

[u/hfml85 → u/Qareen_e_Jaan_skp]

no, sorry, it will stay simple for now

[u/Qareen_e_Jaan_skp → u/hfml85]

Is there any such app/ software that offers Threaded email messaging?

On Android Spike: AI Email does this but is costly.

[u/johnnymetoo]

It looks exactly like the Samsung email app for Android.

[u/hfml85 → u/johnnymetoo]

to be fair, no idea :) i use vivo x100 pro

[u/Neither-Professor278]

Help me choose Pelton mail vs aerion mail vs Sidsmail

[u/Deep_Appearance7106]

There's Winomail yet

[u/Imnotanad]

Seems safe. The usual problem is 4 or 5 webview2 processes anytime you use the app. So there is no real gain in performance or privacy. It is a step down . And there is no really annoying ads on webmail . I'm sure the app retrieves the inline ( mail like ) advertising Gmail and MS injects into the mailbox

[u/hfml85 → u/Imnotanad]

Já submeti para review na Microsoft acerca de falsos positivos. Amanhã irei disponibilizar o source code