About Postbox

Postbox is a desktop email application for macOS and Windows.

It's built for power users who send and receive high volumes of email.

Our huge collection of innovative features help people work smarter and more efficiently.

Based in San Francisco, Postbox has been hand-crafting email software since 2008.

Download macOS | Download Windows

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What's New in Postbox 5


Placeholders in Response Templates New


In Postbox 5, you can now add dynamic data fields to Responses, which are pre-canned text/HTML snippets that can be reused within message replies.

Placeholders automatically populate with data from the message itself –or– your own data through the custom fields you create.

Simply press the TAB key to navigate through Placeholders and enter values.

Select Preferences / Composition / Responses / + button, then click {a} to enter a Placeholder.

70 Emails Every Business Needs New


We're including 70 professionally written email Responses that anyone can customize and use.

Customers will receive emails for finding a job, hiring, making introductions, reaching out to investors, sales, and more.

Responses are packaged within a Postbox Add-on which you can download here, then accessible from the Responses menu in the Compose window.


Quick Post New

Many web sites allow you to send content to their service using a custom email address and/or tags in the subject line to facilitate routing.

But remembering all of these addresses and manually entering the tags can be a pain.

Quick Post helps you organize and use send-to-service email addresses. Setup multiple addresses, then add any desired tags to the subject line.


Then, select a Quick Post action to send the message to the service in the background, without the need to open a compose window.

You can even set your Filters to run a specific Quick Post action to create the ultimate workflow.

Available in Preferences / Advanced / Quick Post.

Global Filters & New Filtering Options New


Now when you create a new filter in Postbox, you can set the filter to either run per account, or "globally" across all accounts.

Additionally we've added the several new options for filtering, creating one of the most complete email rule sets on the market:

Filter Criteria

  • by subject
  • by sender
  • by Address Book
  • by Address Book Group – New!
  • by message body – New!
  • by date
  • by priority
  • by status
  • by status is Pending – New!
  • by To
  • by Cc
  • by age in days
  • by size
  • by Topic – New!
  • by has attachment – New!

Filter Actions

  • add Topic
  • remove Topic – New!
  • move message
  • copy message
  • forward message
  • reply with Template
  • Quick Post – New!
  • play sound file – New!
  • run AppleScript (macOS only) – New!
  • mark as Read
  • mark as Unread – New!
  • mark as Reminder
  • mark as Not Reminder – New!
  • mark as Pending – New!
  • mark as Not Pending – New!
  • set priority
  • set Junk status
  • delete message
  • stop filter execution

Anti-Tracking New

To provide you with more privacy, Postbox 5 has a new "Anti-Tracking" feature that will alert you when tracking tools are used within a message.

Use Anti-Tracking to prevent pesky salespeople from knowing if, and when, you open a message.


Image Scaling + Message Size Indicator New

The Image Scaling feature in Postbox 5 resizes large inline images with just a few clicks.

Select an image to be resized, then click on a resize icon to scale the image down. Deselect the resize icon to revert the image to its original size and resolution.

What's unique about the Postbox approach is that image scaling can be performed on a "per-image" basis, as opposed to the all or nothing approach found in some other email clients.

The message size indicator will display the total message size, including text and images.

Since ISPs have size limits for messages sent through their servers (for example, Gmail places a 25MB limit), Postbox can be set to display a warning if you exceed a certain threshold.

Image Effects New

Postbox 5 contains a number of Image Effects that will enable you to create beautiful emails and newsletters. Effects include scaling, float, margin, flip, rotate, photo effects, frames, and shadow.

Postbox Image Effects@2X
Emoji Panel@2X

Emojis New

Insert Emojis into messages has never been easier. 

Simply type a colon, followed by the name of the Emoji you wish to use, then auto-complete against a selection.

macOS Touch Bar Support New

Postbox supports the macOS Touch Bar for newer MacBook Pro laptops.
The Touch Bar actions are both unique to Postbox and common to other apps for functions such as bold, italic, etc.

Tb Main@2X

25 Beautifully Designed Signature Templates New

As an added bonus, Postbox now includes 25 beautifully designed email signatures that will present you in the best light possible. We've included designs of all shapes, colors and sizes.

Each signature is fully customizable, and contains all the code examples you need to make a big impression.

Signatures are packaged within a Postbox Add-on which you can download here, and are accessible within the Signatures menu in the Compose window.

Other New Features...

Improved Favorites Bar

  • Drag and Drop move of Messages to Favorites Bar Folders
  • Reordering of Favorites Bar Folders
  • Highlight Search Scope in Favorites Bar

New Storage Option for Topics, Signatures, Responses, and Address Book

Auto-Image Rotation and New Image Picker

New Importer for Local Mail Files

macOS Share Menu Support



Other Key Features


Account Groups

Most email clients provide "universal" or "unified" folder views, but it is usually an all or nothing proposition that mixes work and personal emails together.

Postbox lets you organize accounts into "Account Groups," which gives you an unlimited number of ways to unify your views. For example, you can have group for "work" accounts and another for "personal" accounts.


Focus Pane

The Focus Pane lets you focus on what's important by temporarily hiding everything that isn’t relevant to the task at hand. For example, you can use the Focus Pane to view:

  • Unread messages from my boss
  • Reminders from this month
  • Messages from Sally with tag Project X

The Focus Pane zeros in on messages by attribute (such as being unread or having an attachment), contact, topic, and date. These criteria can be mixed and matched to fine-tune the view.

The Focus Pane is also fully customizable–you can hide or show attributes, add favorite contacts or Topics, and reorder them by priority.

To view the Focus Pane type command/control-shift-p, or select Show > Focus Pane from the View menu.


Powerful Tagging

Postbox fully embraces message organization and management via tags/keywords, which we call "Topics."

Most importantly, when you assign a topic to a message, it's also applied to other messages within the conversation, in addition to all future replies — a huge time saver.

To assign a Topic, select a message and press the "t" key, or manage topics in Preferences / Display / Topics.

File and Image Search


Can't find the document or photo? No worries! Postbox gives you fast access to documents and images hiding within your email messages — no more digging through email messages to find what you need!

And once you've found what you're looking for, Postbox lets you save or send the file with just one click.

Click the View buttons in the toolbar, or select a content type from the View menu.


Quick Move

If you are familiar with Spotlight on the Mac, Quick Move works similarly for moving messages. It is THE secret weapon for fast message triage.

When viewing a message, simply type the "v" key, start typing the name of the target folder, then autocomplete against the name. That's it! It works really, really fast!


Full HTML Editor

Postbox Code View provides full HTML visualization, editing, and fine-grained control over the messages you author, or the pre-canned Responses and Signatures you create.

Code View is powered by CodeMirror.net, which supports syntax highlighting, auto-complete, and themes.

In the Compose window, click the </> button in the Formatting Toolbar, or select Code View from the View menu.


Cloud File Sharing

Our Cloud File Sharing add-on enables you to send links to your Dropbox, Box, and OneDrive files instead of sending the files themselves.

Simply drag and drop a file from your storage folder into the body of a message and a link to that file will be created automatically.

Enable your accounts in Preferences / Attachments / Outgoing.

Compose Power Tools

1) Domain Fencing

Domain Fencing helps prevent users from making two common email mistakes. It provides a warning if you a) address a message outside of a desired domain or domains, or b) are using the wrong account when you address a message to a certain domain or domains

The domains are specified per account, which provides for fine-grained control over how you're notified of a potential addressing mistakes.

2) File and Image Search

Postbox lets you find and use files and images hiding in your mail – even while you’re composing a new message.

3) Summarize Mode

Summarize provides a clean and beautifully formatted who-said-what-when email that helps message recipients keep track of long email threads.

4) Composition Goals

Composition Goals feature provides a user-configurable character/word counter and stopwatch that indicates to users when a message being written exceeds a desired length, or has taken too long to write. Goals feature provides the feedback you need to increase your time management awareness and keep you on track.

Core Features


Create a set of pre-written responses to streamline your work. When you find yourself replying over and over to common inquiries, such as in customer service or sales roles, these can save valuable time. Responses can include text, HTML formatting and images, perfect for brochures, price sheets, portfolios or any content that drives your business.

Inspector Pane

The Inspector Pane summarizes the content it finds in messages or conversations, including files, images, links, tracking numbers and more. It's like a discovery engine built right into your email.

Quick Reply

Quick Reply lets you reply to a message without the need to open a compose window – perfect for short, snappy responses like "I'll see you at eight," or simply "Thanks!" And it all happens inline within a message or conversation.

Message Editing

Edit any message by pressing the Action button within the message header. Update the status of a Reminder without having to send a message to yourself. Change the message subject or any part of the message body, and when you're finished, you can either save your changes or create a copy to preserve the original.

Mailing List Unsubscribe

If Postbox detects a "List-Unsubscribe" attribute in a message header, it displays an Unsubscribe link next to the sender’s address, so you can unsubscribe with a click.

One Click Archive

You can move messages from the Inbox to a dedicated Archive Folder by clicking the Archive button in the toolbar, or by typing the letter "a" when viewing a message. Combine the use of the Archive Folder with advanced search to keep your Inbox clean.

Send and Archive

Send and Archive is one command for the following actions … drumroll please… Send and Archive. Supported in both Quick Reply and Compose windows, it's a great way to keep your inbox tidy.

Quick Folder Switch

Jump to another folder using your keyboard with Quick Switch. While viewing messages, type "g" to bring up the Quick Switch window, then start typing the name of the folder you would like to switch to, such as "Sent." Postbox will auto-complete and display corresponding accounts.

Social View

Postbox's Social view lets you browse updates from your social networks, perfect for monitoring your brand, killing time during lunch, or when you're in power triage mode and need to clear out unnecessary clutter.

Subscription View

The Subscription View organizes messages from the services you subscribe to, and presents them in one convenient view.

Exceptionally Customizable

Postbox's Preferences contain probably the most extensive set of pro features and settings you’ll see in an email app. They afford you unequaled control of Postbox’s behavior, allowing you to achieve email mastery like no other app.

Conversation View

Postbox gathers message fragments from multiple folders and presents them in a unified view. Quickly bring yourself up to speed and jump into discussions with all the information and context you need to stay on top of your work.


Do you leave messages in your inbox to remind you of things to do? Postbox lets you create reminders where it matters most — your Inbox! Create new reminders, annotate existing ones, and then pin reminders to the top of your message list so they're not forgotten.

Favorites Bar

Quick access to your favorite accounts or folders, similar to the bookmarks bar in a browser. To add a folder to the Favorites Bar, simply drag and drop the folder into the bar.

Tabbed Workspace

It works for browsing the web, and it works for email too. Open almost anything in a tab, including messages, folders, topics, contacts, attachments and images. Quickly switch between and shuffle as needed.

Smart Address Auto-Complete

Find contacts by first name, last name, or domain right from the Addressing Widget. Additionally, it will pull in any profile pictures it finds within the address book.

URL Auto-Complete

Type "http" or "www" in the Compose window and Postbox will auto-complete the URL from the links it can find from your messages.Thus, your entire mail store now serves as a database for links that you can easily share with others.

Customizable Quote Colors

Make individual replies stand out visually. Set Postbox to display up to five quote levels in colors of your choosing.

Awesome Gmail Support

Google labels, Important view, Gmail shortcuts, adding detected dates to Google Calendar

Flexible Layout

Preview messages to the right of the message list, or below. Show all panes to see everything at once, or hide them for a minimalist view.

Anti-Phishing and Malware Services

Postbox helps protect users from viruses, spyware, and trojan horses by checking URLs received in emails against a local database of suspected phishing or malware sites. The database is automatically updated every 30 minutes, and if a potentially malicious URL is identified, a warning message is prominently displayed.


Postbox 5 supports the use of plug-ins we call "add-ons," including the free Cloud File Sharing add-on that adds Dropbox, Box, and OneDrive support.

RSS and Newsgroup Support

Identities (also known as Aliases)

Date, address, phone number, and package tracking number detection

Full Suite of Keyboard Shortcuts

Purchasing & Licensing Details


Postbox 5 is sold direct to consumer via our Postbox Store. The retail price is $40 and upgrades from previous versions are $28. Volume discounts apply when two or more licenses are purchased.

Licensing Details

Postbox licenses are per user, so one license will cover any/all machine(s) you personally use, on Mac, PC or both. If more than one person will be using Postbox, then additional licenses can be purchased at a discount.

Trial & Guarantee

Postbox offers a free 30-day trial plus a 30-day satisfaction guarantee, providing customers with a total of 60 days to evaluate Postbox without risk.

Company Background

Company Formation

Postbox, Inc. was founded by Sherman Dickman and Scott MacGregor in December of 2007, and is based in San Francisco, California. Postbox was first announced at the TechCrunch50 conference in September, 2008.

Founder Bios

Sherman Dickman, Founder — Sherman teamed up with his co-founder, Scott MacGregor, after serving as Director of Product Management at Mozilla Corporation. Sherman joined the Mozilla team from Sun Microsystems, Inc. where he spent seven years in product management and strategic marketing roles within the Java Software Divisions. Prior to Sun, Sherman held product and program management roles at Broderbund, Inc. and Apple. Sherman holds a degree in English from the University of California, Los Angeles.

Scott MacGregor, Founder — Leveraging his prior decade of experience in developing email applications for Netscape and Mozilla Corporation, Scott created Postbox to make emailing more powerful and efficient. Prior to founding Postbox, Scott was a lead engineer at Mozilla Corporation, where his after-hours efforts led to the invention of Thunderbird. Scott started out his career developing email and messenger products at Netscape. Scott holds a Masters in Engineering from the Massachusetts Institute of Technology.