fluentCRM
Paid
Self-Hosted Email Marketing Automation für WordPress ohne Limits
Communication & Collaboration
11 curated tools in this category
Team communication decides whether information arrives or seeps away in inboxes. This category covers tools for chat, video calls and email, with a current focus on self-hosted email and newsletter tools like Listmonk and Mautic. If you are looking for a Slack alternative with data ownership, or want to move your newsletter sending from a US service to your own server, this is the place to start.
The selection is still small and growing. In return, every tool has its own detail page with strengths, weaknesses and context. What matters in communication software, from deliverability in email sending to the question of data export, is covered in the guide below the tools.
Communication & Collaboration
Plunk
Open Source
Open-Source E-Mail-Plattform für Transaktionsmails und Marketing-Automation
BillionMail
Open Source
Open-Source E-Mail-Server für Newsletter und E-Mail-Marketing ohne monatliche Gebühren
Notifuse
Open Source
Open-Source E-Mail-Marketing-Plattform als Mailchimp-Alternative
Dittofeed
Freemium
Open-Source Customer Engagement für automatisierte Multi-Channel-Kommunikation
keila.io
Open Source
Open Source Newsletter-Tool mit EU-Hosting und voller Datenkontrolle
usesend.com
Freemium
Open-Source E-Mail-Plattform für Transaktions- und Marketing-E-Mails
Sendportal
Open Source
Open-Source E-Mail-Marketing-Plattform für vollständige Kontrolle
Mautic
Open Source
Open-Source Marketing Automation für maximale Kontrolle
Listmonk
Open Source
Open-Source Newsletter & Email Marketing Platform für maximale Kontrolle
AFFiNE
Open Source
All-in-One Workspace: Notizen, Dokumente und Kollaboration vereint
What is communication software?
Communication software covers everything that moves messages between people: team chat and video calls on the synchronous side, email and newsletters on the asynchronous one. This category gathers mostly open source tools you can host yourself, which keeps message content and recipient lists on your own server instead of with a cloud provider.
Typical use cases
Newsletters on your own terms: Listmonk sends newsletters and campaigns from your own server. The subscriber list lives in your database, and costs scale with SMTP volume rather than list size.
Marketing automation: Mautic models multi-step email journeys, such as onboarding series or reactivation campaigns, and is among the most mature open source options in this field.
Team chat with data ownership: If you want a Slack alternative because chat history contains business internals, self-hosted services like Mattermost or Rocket.Chat are the usual destination. The message history then belongs to you and does not end up behind a paywall.
What matters when choosing
Deliverability: In email sending, it is not the software that decides whether you reach the inbox, but the reputation of the sending server. Plan for SPF and DKIM setup plus an established SMTP service, or your newsletter lands in the spam folder.
Data ownership and GDPR: Recipient lists and chat histories are personal data. Self-hosted tools simplify the GDPR assessment because data processors and third-country transfers drop out of the picture.
Export and lock-in: Before adopting a tool, check whether subscribers and histories can be exported completely. Otherwise a later switch becomes a migration with losses.
Frequently asked questions
Which Slack alternative is open source?
Mattermost and Rocket.Chat are the best-known self-hosted Slack alternatives, both with channels and threads. For small teams a leaner approach is often enough, for example a self-run Matrix server.
Is a self-hosted newsletter tool worth it?
The bigger the list, the sooner it pays off: many SaaS services charge by subscriber count, a self-run Listmonk server does not. The privacy advantage comes on top. The price is operational work, mainly updates and maintaining your sending reputation.
The selection here is still small and growing, currently focused on email and newsletters. If sending is your topic, you will already find a useful range above; for chat and video, a second visit later will pay off.
