Built around newsletters, not inbox triage.
Email clients are excellent for sending, replying, forwarding, and getting through messages. Letterboxx is built for reading, collecting, highlighting, and returning to newsletters.
Email newsletter app.
Turn the newsletters you already receive into a calm, organized reading library on your Mac.
Your newsletters, minus the inbox.
A dedicated Mac app for the things you actually meant to read.
Clean View does the tidying.
Trim trackers, ads, embeds, and clutter before they reach your eyes.
Highlight like you mean it.
Save the good bits in familiar colors, right where you found them.
Give every newsletter a home.
Letterboxxes work like folders, keeping subscriptions stored, sorted, and out of your inbox.
Flip to the nerdy side.
Reveal sender, source, composition, and Clean View details without leaving the reader.
Let the mail sort itself.
Simple Auto-Delivery rules send recurring newsletters where they belong.
Make the list feel like yours.
Adjust type, density, badges, dates, and status icons until it feels right.
Keep your library tucked away.
Encrypted backups protect newsletters, Letterboxxes, rules, highlights, and settings.
Choose your reading mood.
Light, dark, e-ink, newspaper, Kitty Cat, and more. Because this is a Mac app.
Email newsletter app
A Mac app for the newsletters you already meant to read.
Letterboxx turns incoming newsletter copies into a focused reading library, so subscriptions stop competing with receipts, alerts, work mail, and everything else your inbox has to carry. If you want the reading-first view, start with the email newsletter reader; if you want the Mac-specific workflow, see the newsletter app for Mac. For the thinking behind the app, read the Letterboxx letters.
Works with the mail you already use.
Connect Gmail or IMAP accounts, choose the folders that contain newsletters, and download local copies while original messages remain on the mail server unless you delete them.
A searchable library for saved ideas.
Sort recurring newsletters into Letterboxxes, use Clean View when email HTML gets messy, save highlights, and search across the issues you have kept.
From email to library
Keep email for communication. Use Letterboxx for subscribed reading.
An email newsletter app should not make you abandon your inbox. Letterboxx works beside the email accounts you already use, importing local copies from selected folders so newsletters can become a reading library without disrupting normal mail.
That also makes it easier to organize email newsletters by topic, sender, or habit once they are outside the inbox.
- Connect the account that receives newsletters. Gmail and IMAP accounts can provide the folders or labels where newsletters arrive.
- Choose only newsletter sources. Import from the places that contain subscriptions, not every message in your mail account.
- Read, organize, highlight, and search. Letterboxx turns recurring issues into collections you can revisit after the inbox has moved on.
App details
What an email newsletter app should make easier.
The point is not to replace email. The point is to give newsletters the reading tools that email clients usually hide behind mail-management workflows.
Newsletter organization
Sort subscriptions by topic, sender, or reading habit.
- create Letterboxxes for topics like tech, investing, local news, or essays
- route recurring senders with Auto-Delivery rules
- filter by reading state, highlights, sender, or favorites
Reading memory
Keep useful ideas available after the issue is read.
- save highlights directly inside the newsletter reader
- use Clean View when newsletter HTML gets noisy
- search the local library when you remember an idea but not the issue
Email is for communication.
Letterboxx is for reading.
Your email inbox is built for messages, replies, and triage. Letterboxx is built for essays, digests, roundups, research, and the publications you actually meant to revisit.
How it works
Connect your email. Read local copies.
Pick the mail folders that contain the things you want to read. Letterboxx downloads local copies into your Mac reading library, while original messages remain on the mail server unless you delete them.
What changes
Your newsletters do not change.
The way you use them does.
Instead of treating every newsletter like another inbox item, Letterboxx turns recurring subscriptions into collections you can read, highlight, search, and keep.
Your inbox is good at
- Sending and receiving messages
- Replying and forwarding
- Processing the inbox
- Getting back to zero
Letterboxx helps you
- Build collections around topics
- Route newsletters automatically
- Highlight useful ideas
- Search across years of saved issues
- Read without inbox chaos
Download Letterboxx for Mac.
Start with 14 days free before deciding.
Take a tour of your newsletter library.
Click through Dashboard, Newsletter, Clean View, Message Diagnostics, Backup & Restore, and Highlights to see how Letterboxx turns email newsletters into a calmer Mac reading space.
Letterboxxes
Letterboxxes are your custom newsletter folders inside Letterboxx. Create focused spaces for each topic, then file newsletters manually or route them automatically with Auto-Delivery.
Focused Organization
Give every newsletter a purpose-built home.
Separate your reading stream into intentional Letterboxxes so your inbox stays clean and your best newsletters stay easy to find.
- Create Letterboxxes for topics, projects, or interests
- Move newsletters directly into a Letterboxx using the contextual menu or drag and drop
- Use Auto-Delivery rules to route new messages into the right Letterboxx automatically
Quick Access + Simple Setup
Create and manage Letterboxxes in seconds.
Letterboxxes live directly in the sidebar and can be created on demand, so setup and organization stay one click away.
- Open sidebar actions to create and manage your Letterboxxes instantly
- Name and configure a new Letterboxx in a focused modal flow
- Keep your Letterboxx system aligned with how you actually read using sort or drag and drop
Clean View
Newsletters should feel like reading, not like loading a miniature website full of scripts, embeds, and tracking pixels. Clean View gives you a calmer reader with visible privacy reporting.
Cleaner Reading
Strip the noise before it reaches your attention.
Clean View removes common newsletter clutter and keeps a local audit of what was taken out so the reader stays fast, quiet, and explainable.
- Blocks or sanitizes trackers, ads, scripts, autoplay media, embeds, and remote images
- Tracks per-message, sender, and all-newsletter removal counts
- Offers Off, Medium, High, and Custom privacy modes for different reading preferences
Privacy Report
See the work happening behind the quiet.
The Clean View settings pane surfaces cumulative totals and attribution so privacy protection feels transparent instead of mysterious.
- Totals for observed messages, sanitizer removals, trackers and ads, and privacy intelligence
- Source attribution for blocking-list matches when Letterboxx can map them locally
- Backfill tools for keeping Clean View reporting accurate across older newsletters
Diagnostics without leaving the reader.
When a newsletter looks different than expected, Letterboxx can explain the message, Clean View changes, delivery state, and source details right beside the reading flow.
Message Diagnostics
Inspect the current newsletter inline.
Message Diagnostics now flips into the reader pane, so you can understand a selected newsletter without opening a separate utility window.
- Review identity, composition, raw source availability, and Clean View summary details
- Use the same toolbar and keyboard path from the reader
- Keep diagnostics tied to the newsletter you are already reading
Activity Center
Keep delivery and maintenance visible.
Activity Center gives important app events a dedicated place, so import, routing, highlight, and maintenance details stay understandable.
- Review recent activity when delivery or rendering needs context
- Keep diagnostics and operational events separate from focused reading
Automation, accounts, and safekeeping.
Letterboxx is still local-first, but it gives you practical controls for routing newsletters, importing copies from mail accounts, choosing read-status behavior, and protecting your library.
Auto-Delivery
Rules that keep the library tidy.
Auto-Delivery routes new arrivals into the right Letterboxx using ordered rules you control.
Accounts + Sync
Clear setup, honest sync status.
Connect Gmail or IMAP accounts, import newsletter copies from selected folders, and see what iCloud-backed continuity can do when available.
Backup + Restore
A real safety net for your reading library.
Create encrypted backups for newsletters, Letterboxxes, Auto-Delivery, highlights, reminders, and settings.
Appearance
Tune Letterboxx to your reading style with theme controls, typography settings, and calmer visual defaults.
Visual Theme
Choose the look that matches how you read.
Switch themes instantly and keep your reading experience aligned with your environment and focus level.
- Theme modes include System, Light, Dark, Newspaper, E-Ink, and Tiger
- Quickly preview and switch without leaving your reading flow
Newsletter List
Tune sizing, density, and visible detail.
Adjust the newsletter list so it surfaces exactly the information you want at a glance.
- Choose the list font and row density
- Set subject size, secondary text size, and sender badge size independently
- Toggle sender name, date and time, status indicators, and unread indicator visibility
Highlighting
Save important passages in any newsletter, keep them attached to that message, and use View Highlights to jump through them later.
Mark what's important
Save the passages worth coming back to
Select text in the reader and save it as a highlight without leaving the newsletter.
- Highlights stay attached to the newsletter where you saved them
- Use View Highlights to jump through saved passages in order
- Recolor or remove highlights whenever you revisit the message
Persistent Recall
Find newsletters with saved highlights later.
The Highlighted filter shows newsletters that contain saved highlights, so the ideas you marked are easy to find again.
- Highlights persist per message across app sessions
- The Highlighted filter shows newsletters with saved highlights
- Recolor or remove highlights whenever you revisit the message
Questions
Email newsletter app FAQ
Is Letterboxx an email client?
No. Letterboxx is a dedicated Mac app for reading and organizing newsletter copies. Your normal email app still handles everyday mail, replies, and sending.
Does Letterboxx move my original emails?
No. Letterboxx connects to your email account using IMAP and downloads local newsletter copies into a reading library on your Mac. Original messages remain on the mail server unless you explicitly delete them.
Can I organize newsletters into folders?
Yes. Letterboxxes are topic-based spaces for newsletters. You can file newsletters manually or use Auto-Delivery rules for recurring senders.
Can I highlight passages in newsletters?
Yes. You can select useful passages, save highlights in familiar colors, and return to highlighted newsletters later.
Is there a free trial?
Yes. Letterboxx offers a 14-day free trial before you choose a monthly or annual plan.