And the winner is... Thunderbird!

One thing that I didn’t want to do on my new Mac Mini was using Rosetta apps. Why should I? :wink: So when I noticed that there isn’t a Apple Silicon version of my current e-mail client Postbox, I had to search for something new. No subscription, no sending my mail to unknown servers, a good rule engine, those were my main requirements. Labels (as in proper IMAP tags, not the labels that Apple Mail uses) would be a plus.

And much to my own surprise I ended up with Mozilla Thunderbird. The new “Supernova” version 115 is really good. And in some respects better than Postbox.

So if you’re looking for a good e-mail client on the Mac, and one that’s free too, don’t forget to look at Thunderbird.

It ain’t perfect (for me). But no e-mail client that I looked at so far is. But it’s more powerful than Apple Mail, looks okay (Apple Mail is looking slightly better) and does the job.

On my wishlist is more granular handling of the Unified folders (just inboxes will be fine


The new cards feature is basically one of the sole reasons I used Postbox (as it mimics Outlook, letting me see information about the email before I open it, rather than just the sender/title), so it’s something I’ve been playing with on my Windows box. My Windows version is also using Maildir, rather MBOX, to test that out.

I also no longer work for a firm that requires me to file all emails in to a project folder, so the quick file function of Postbox is not as important anymore.

+1 from me

I am not happy with Apple Mail because I have a lot of contact with non-Apple users. No matter what mail software they use, Apple Mail creates emails that are not displayed nicely on their devices, especially when attachments are involved. And yes, I know about Send attachments to Windows users in Mail on Mac - Apple Support and Add attachments to emails in Mail on Mac - Apple Support (adding attachments at the end of mail). So, I caved - I was trying to use Outlook for some time, but the Mac version is not doing it for me either. After having looked into all those “cool” Mac third-party clients, it took some time until I started using Thunderbird early this year. No need to look anywhere else: it does everything I want and it does it well. And Supernova does actually look quite nice, too.

+1 from me too.

I have multiple email addresses in Thunderbird – including two that aren’t Gmail.

Also, Thunderbird uses my Apple Contacts smoothly.


I’m interested in trying it, but as there is not currently an iOS client, how does everyone handle mobile access to emails if you have switched to Thunderbird on MacOS?

I am using Apple’s native iOS client.

All my email accounts are using IMAP, so it does not matter what client I am using on whatever platform. Sometimes I do use Apple Mail on my Macs, too. It does not matter.

When I am writing an email, Thunderbird is very often my choice if I am writing on my Mac, and that is where I am doing most of my writing stuff most of the time.

1 Like

If you are using an IMAP server, you could use Thunderbird on desktop and (or your favorite iOS mail client) on your phone.


You don’t have to use the same email client on all machines. In fact, you can use multiple clients on the same device to attach to the same email server.

I use iOS Mail and Fastmail on my iOS devices; and Apple Mail, Microsoft Outlook, and of course Safari browser on mac’s.

1 Like

I have tried Thunderbird, primarily because it can handle vast amounts of emails (500K+). However I could not find a way to increase the font size in the sidebar list, the messages list and I find the font size way too small. Only thing I could find it how to increase the font size in the message reading pane.

One suggestion was to go into Preference > General > Advanced and change some code in the dev.css section. I shouldn’t be required to get into the weeds in order to do such a basic function.

Any suggestions would be appreciated.

1 Like

I looked at it yesterday after having had a lifetime licence for Postbox, and having used it intensively, for ten years. After downloading and installing Thunderbird 115 I’ve spent time tailoring it and am very pleased with it. I propose to move back to it (I used it before Postbox) for the following principle reasons:

  • The Postbox developers have shown no interest in developing an Apple Silicon version of Postbox—with the result that Postbox hangs, one or twice a week, when I try to quit it on my M2 MacBook Pro.
  • Postbox invariably refuses to allow the language setting to stick at "English (United Kingdom)” and constantly reverts to US English, which is infuriating.
  • The "Correct Identity” add-on in Thunderbird 115 is a much more helpful implementation of tailoring identities to specific email addresses than the manner in which Postbox dealt with that.

All in all, I’m very pleased with the move.


It took me a lot of probing around but I eventually found that View → Font Size → Increase Font Size worked for me.



Thanks for the now obvious insight. Being a Mac user, I instinctively looked in Preferences, then did a Google search. I need to remember, that Thunderbird has a long Windows / PC background.

Thanks again

Another question for the group: has anyone used the QuickFolders add-on?

Yes, I used it a couple of years ago.

The plugin is very good and offers powerful customization options. Not to demerit the developer, but I find it hard to pay for a functionality that should already be present in Thunderbird.

I was going to raise the exact same question in this thread: is still thunderbird unable to autocomplete folders when moving / archiving emails? I think I remember Postobox had developed it.

Postbox was initially based on Mozilla Thunderbird… :wink:

By the way, you’re right. The latest version is stellar in nearly every single way.

Just look at how nice the user interface is!

By the way, I find it funny that you created this topic shortly after I created mine. Would you ever use an iOS version of Mozilla Thunderbird?

Don’t worry - that’s exactly what I did too before discovering the answer somewhere I cannot now recall. :grinning:


Yes, I think you can’t do that in Thunderbird 115, sadly. All I’ve discovered so far is the right click where the "Move” menu displays a list from which to choose. Your recollection of Postbox is correct and I miss the easy move option (partly because I use a number of idenitites and various folders linked to them so am frequently moving emails around).

As I’ve not used Thunderbird for ten years I’m not up-to-speed on add-ons but am currently keeping an eye on the "Quick Folder Move” add-on for when it’s updated to work the TB 115—to see how much that helps.


I must say that the interface in the image looks slightly better than dark mode irl. As is stated in their blog: this image is a mockup. They’re apparently still working to make the real interface look like this one.

I don’t use iOS (on an iPhone that is). Only iPadOS on which I’m using Apple Mail. Since I’m only just checking incoming mail on the iPad, Mail is just fine.

I’ve noticed that it doesn’t handle iCloud Mail’s folder structure in the way that you would expect it to. It doesn’t recognize the “Deleted Messages” folder as the “Trash” folder (among other issues). Has anything changed in the latest version?

Will you install the iOS version of Mozilla Thunderbird once it’s released?

In the meantime, I’m just using the default email application. That’s what I’d recommend to most people.

It’s improving with every passing year. Have you considered contacting the developers with your feature request?

If you ask them on social media, you’ll likely receive an answer within 48 hours.

It excites me to think that the redesign isn’t even finished yet! I can’t wait to see what the finalized version looks like! :star_struck:

Oh, okay. I can only assume that it would be compatible with iPadOS too.

Thanks for posting this! I haven’t looked at Thunderbird in a long time and the latest version looks great and fixes the problems that drove me away. I’ve installed it on my two Macs and will give it a try for a couple weeks to see if I want to make the switch permanently.