Email lies at the heart of our business -- customer support and customer contact is critical to our survival. This is not something that can be relegated to a Web UI or just any old client interface. Thunderbird provides small organizations (like ours) a free Email client that is full-featured, fast, and efficient. I can't imagine trying to use anything else!

The Thunderbird Email client provides a fast and easy way to corral multiple Email addresses. With support for POP3 mailboxes, you can pull your data off the Email server and retain/manage it all locally, which is great when you have to travel and may not always have access to the Email server, or for when you want the extra security of getting the data off of the Internet quickly. With IMAP support, you can enable access to a shared Email queue, allowing multiple employees to see and respond to the inbound messages -- ideal for a customer-facing "Sales" or "Support" queue -- and every user can see and search on every reply. All local messages and attachments are stored in a local profile folder, which can be easily moved to a NAS, allowing you to access the Email profile from any machine on the network. You can also synchronize your profile to your laptop so that all of your Email can travel with you into the field, even while disconnected. Add in the intuitive user interface, multiple-calendar features, a solid address book function, and you have an Email client that is hard to beat. Since it's free to use, this makes it even better!

Like with any software solution that you've used for 10+ years, the product does evolve, and they change the UI from time to time. These "improvements" may be beneficial to most users, but moving things around in the UI can slow you down, and the changes can sometimes break automation scripts that rely on specific sequences of keystrokes. Luckily, these occur only about every 2 years or so. Another issue I have is with the built-in calendar. Sometimes it captures an Event from an EMail with an ICS attachment -- and sometimes it doesn't. Apparently, Microsoft Teams doesn't send properly-formatted messages, so this is most often broken, but you can always work around it through manual data entry.

Since I have been using Thunderbird, I never regret my switch from Outlook. Over the years, although the development has not been fast, it has been fast enough for the product to adapt, at least in functionality, to what every mail client must deliver to its user.If you are looking for a robust free email client, Thunderbird is the best option.

I am sure that many people like me came to this product because it is the Mozilla Foundation behind it. We all know how they think about their product, making privacy their flagship. In the case of Thunderbird, you can find a robust email client with functionalities at the level of many other paid clients. If I need to list Thunderbird's advantages, I will start by talking about its extensibility, making it one of the first email clients you can improve and customize with free third-party add-ons. Another great addition of the last years was the "Smart folders," making your multiple account inbox easier to visit and search.Right now I am using Thunderbird for all my personal emails, and the client has all you need to manage successfully all your personal data flow.Thunderbird is free, and for sure is the best option for email clients at this tier.

I will list the things I think can be improved in Thunderbird, but I repeat, we are in front of a robust FREE client, so please consider this when you read about the following points.Complexity: While Thunderbird's extensibility is a strength, it can also be a weakness. The sheer number of options and settings can be overwhelming for less tech-savvy users, and it may take some time to configure it to your liking. This one was my first problem after I switch from Microsoft Outlook.Aesthetics and UI: For me, this is a big problem. While this is subjective, and the interface can be customized, when you open Thunderbird you are looking at a user interface that has not been modernized according to the times.No Native Mobile Application: On June 22, Thunderbird announce the partnership with K-9 email to make real the Android native mobile application, until now, this not happens. Almost all people manage their emails on the go from their smartphones, so again, this is a must for a modern email client.

Overall, Thunderbird is a feature-packed email management solution that provides advanced email features and customization options for individuals and small businesses. It is a free and open-source application that supports multiple email accounts, integrates well with other applications, and provides robust security features. However, some users may find the user interface to be complex and the performance to be slow on older computers.

Customizable: Thunderbird Mail is highly customizable, allowing users to personalize their email experience by choosing from a wide range of themes, plugins, and extensions.Advanced Features: Thunderbird Mail offers advanced features, such as message categorization, quick search, and email filtering, which make it easier for users to manage their email and prioritize important messages.Support for Multiple Accounts: Thunderbird Mail supports multiple email accounts, allowing users to manage all their email in one place, reducing the need to switch between multiple email services.Integration with Other Applications: Thunderbird Mail integrates well with other applications, such as calendars, to-do lists, and news readers, allowing users to streamline their workflow and manage their tasks more efficiently.Free and Open Source: Thunderbird Mail is a free and open-source application, which makes it a cost-effective solution for individuals and small businesses.Cross-Platform Support: Thunderbird Mail is available for Windows, Mac, and Linux, so users can choose the platform that best suits their needs.

Complex User Interface: Some users may find Thunderbird's user interface to be complex and difficult to navigate, especially if they are not familiar with advanced email features.Slow Performance: Thunderbird may run slow on older computers, especially when managing a large number of emails and attachments.Limited Mobile Support: Thunderbird does not have a dedicated mobile app, which may make it difficult for users to access their email from their mobile devices.Lack of Cloud Integration: Thunderbird does not offer cloud integration, which may limit its usefulness for users who need to access their email from multiple devices.Limited Customer Support: Thunderbird is an open-source project, which means that customer support is limited and users may have to rely on online forums and community resources to get help.Compatibility Issues: Thunderbird may not be compatible with all email providers, which could limit its usefulness for some users.

Haven't found a better alternative to manage dozens of emails in one spot. Differentiates each of them in a much better way than others.

No native integration with google calendar, have to use a plugin, but still wish the calendar had a better overview.

Thunderbird handles multiple email accounts. There is even a chat feature. It sorts my email. It removes the Spam and Junk correctly. It archives and stores my past emails and keeps them where they can be searched and accessed at any time. A life saver finding old emails once again!

Thunderbird is so easy to setup. Also if there is an option you want included such as a calendar or todo list or whatever, it integrates easily with add-ons and tools. There is nothing missing when it comes to this power tool!

The software has never let me down. There is nothing to say about "like least". It works. It is easy to learn. And use it every day. And have for YEARS.