I've been trying out Postbox and several other email applications over the past week. Mail with Mail Act-On had been a perfect solution for several years, but that changed with Mavericks.

Postbox is the best of all the apps I've tried. Easily sending emails to folders of various accounts is critical, and Postbox is almost as good as Mail Act-On for this. Most email apps fail miserably at giving you the ability to quickly file messages.

Postbox occasionally lags a bit for some tasks. Indexing a folder seems to take an inordinate amount of time. I was unable to get it to work with an IMAP-enabled Exchange account's outgoing server, although MailMate (which, like Postbox, is not capable of handing Exchange accounts) had no trouble with it.

But no other app comes close as a replacement for Mail.

I just downgraded from Lion to Mavericks and found that Mail no longer supports RSS feeds. I don't want a separate RSS reader as many people are recommending as the fix and went looking for an email app that also has RSS.

On the good side, Postbox has this.

On the very bad side, Postbox has zero support. They claim that support is now only self-help via the FAQs, the guides, and their knowledge-base. There are no support forums, not even community forums, and there is no one-on-one support via email, website or phone. No real support, none, notta. zilch if you have an issue that isn't resolvable with their self-help content, which is really pretty lame for the most part. You will find yourself Googling to try and find someone out there who has asked your questions and been answered with something helpful somewhere on the internet. What you will find are questions and not many answers, you will find some reviews rating the app well done by various online zines. You will find a lot of reviews and rants here and there by people who are very unhappy about a long list of unresolved bugs (and no way to report new ones) and the lack of support. You will find that the app is littered with a mix of seemingly random behavior that for some has resulted in data-loss due to the archiving bug(s).

I tried the app to see for myself, there is a free thirty day trial so go for it, but back up your email with another app regularly. Give the app a spin for a while, for me it was less than an hour in before I found issues preventing me from deleting a folder simply because it has the same name as something else in the trash, can't edit the recipient list went editing a draft, the password database keeps malfunctioning and you have to delete the password for the email account from it and then re-enter it next time you connect, etc. No way to talk to support so I dumped it within two days. And am back to searching a solution.

I would say give it a try, if your expectations are low maybe it will work great for you and you will never miss not being able to contact support and ask why the archive feature sometimes deletes your email and never writes it to the archive and then sometimes works. Why you have to shut down and restart the app every now and then, and other oddities. But, make sure that if your email is important to you, you have it backed up with another app. There are several here on MacUpdate for archiving email.

I was looking for something that would overcome some of the limitations of Apple's Mail. Postbox looked like it might fit the bill. Indeed, it installed easily and bagged all the preferences from Mail. The problem arose when it took forever to download some emails. Some would download quickly, some would give me a spinning beach ball. After experiencing this on several messages, I chose to stick with Mail. Maybe it's an issue that could have been easily resolved... or not. I didn't have the inclination to putter with it.

Fantastic!

Occasional reboots required to clear stuck emails in out box. And I do mean OCCASSIONAL! This is NOT a deal breaker.

If you're tired of Mac Mail hogging all the resources; if you're tired of using plug-ins to organize your mail; if you just want a faster interface - this is for you.

After some tries with Airmail and two bad experiences with Apple Mail and Mail Pilot, I returned to Postbox. It just works for me. The only issue is that it is slow in opening the first message or not reacts promptly when clicking on the notification banner.
Hoping this last update fixed it. As for the support, I don’t link the model, but googling something like “postbox support email” i found a working mail address and the answered me in a couple of days. Not the quickest, but reasonable.
For italian speakers (and google translate users) see the review in progress by Paolo Attivissimo

Seems like when you move messages from Inbox to another folder (label) in Gmail, it adds the additional label, so that the message will still exist in Inbox.

Which is different behavior than Mac Mail. When you move a message in Mac Mail, it removes the original label.

Does anyone now how to make Postbox's default drag-and-drop behavior a true "move?"

There's definately going something wrong here. When I switched between Classical and Vertical view I first got wrong senders, eg email from MyFonts appears to be sent by Postbox, then I only could select 2 emails at a time or even 3 at a time. Now I see that all mail in column view is listed twice..

Any chance grouping of email by day is going to be emplemented? Please with ability to turn it on/of. Makes browsing email so much easier.