open source EMAIL CLIENTS

How to regain email control in 2020 using ready-to-run open source email clients.

Over the past decade, we’ve seen an almost complete change in corporate mailboxes
from on-premises mail servers to cloud services like Exchange Online (Office 365) or Gmail for business (Google Apps).

The main reasons for it are:

  • the need to access emails from mobile and web interfaces
  • the need to protect mailboxes from spam and malware

In this way, the life of IT professionals has been simplified by offloading
the responsibility to manage the email infrastructure on the “big tech players”.

The risk of abandoning basic email skills, can lead us to think about email
as something that works magically, just because Microsoft and Google handle it.

We can regain email control by breaking down the messaging components and managing them individually:

  • the incoming mailserver
  • the email client
  • the outgoing mailserver

This creates service isolation and segmentation and tremendously benefits security.
Thus, decreasing the attack surface through isolation/segmentation is considered best practice.
Furthermore, it increases the scalability and stability.


Email clients are the primary interface of mailboxes. They’re a complex piece of software that interacts with users.

There are many solutions available on the market, we have selected them based on two requirements:

  • multi-platform, actively managed and open source projects
  • ready to use, so that system administrators can easily manage them

We came up with two choices:

  1. Mozilla Thunderbird Mozilla Thunderbird is an open-source, cross-platform email client for personal computers. Developed by the Mozilla Foundation.
    It supports both IMAP and POP (storing mail locally on your hard drive so that it can be accessed without an internet connection).
    It features excellent mail filter capabilities and management.

    Thunderbird has strong support for using multiple accounts and identities, including automated signature features.
    It comes with ready-to-install versions for: Windows, Mac OS and Linux. To gain access remotely, users must first connect to their computer.

  2. The new Rainloop fork The new Rainloop fork, is a simple, modern, lightweight & fast web-based email client.
    It can handle large number of email accounts without the need of any database connectivity.
    It holds both SMTP and IMAP protocols to easily send/receive emails without any trouble.

    In 2020, the SnappyMail Github project has been published.
    It is the drastically upgraded & secured fork of RainLoop Webmail Community edition.
    Here is the SnappyMail email client demo. If you want to try the Admin interface, contact us.