Comparison

MailCat vs Exo

Price, ratings, monetisation and update history for both apps, side by side — with what reviewers say about each.

Head to head
About

MailCat

This app helps organize your inbox by automatically categorizing emails using machine learning and custom rules. It can filter spam and move messages to designated mailboxes, supporting IMAP accounts.

Highlights
  • Machine learning spam filtering
  • Rule-based email categorization
  • IMAP account support
  • Move emails to specified mailboxes
  • Blacklist and spam learning data
  • Multiple account switching
Features
Read full description

■MailCat is a Mail Categorizer: MailCat is a Mail Categorization App.
 MailCat has two kinds of categorization method --- a machine learning categorization and a rule based categorization.
MailCat can filter out spams from the incoming mail messages by the machine learning categorizer,
and move mail messages to the specified mailbox by rules. MailCat has no mail sending facility and has only support for IMAP. POP/SMS/MMS are not supported. ■How to connect to an IMAP mail server: To connect an IMAP mail server, just specify your full email address as your login name(username) and the password you log in to your account. If you don't know your login name/password, contact an organization or personnel in charge of the IMAP mail server to get a hostname, user id(name), password. ■Basic operation: * Pull down to Refresh/Long Press to reload&spam filtering * Push up to download older mails at the bottom of message lists *Tap/Swipe to switch accounts Tapping/Swiping the navigation bar of the Mailbox list switches the account if multiple accounts are available. * Tap/Swipe to move around mailboxes (among 'Quick View List') * Move/Delete/Mark mail messages by the toolbar on the navigation bar * Tap/Swipe the navigation bar to turn over mail messages * Add a mail to the blacklist/spam learning data by swiping *Tap a Tab bar to switch the rule view. There are 4 views to show the rules for ‘Sender’, ’Subject’, ‘Message’, ‘Compound’. ■Spam filtering: MailCat generates a spam filter by learning from spam and ham messages in INBOX. Just follow the steps, you can have your own spam filter. 1. Tap 'Edit' button in Monitor. 2. Pick up several mail messages by tapping each table cell. 3. Tap "SPAM" button on the command bar. 4. Likewise pick up mails, and "HAM" button on the command bar. 5. "Pull down to Refresh" or "Long press on the navigation bar" triggers Machine learning, then a spam filter will be generated. 6. Repeat the steps(1-5) until the number of spams and hams reaches about 16. 7. After learning 16 spams and 16 hams, MailCat starts judging which mail is spam or not. 8. Check the filtering result on Monitor. 9. Correct errors and 'Pull down to Refresh" or "Long press( 2sec) on the navigation bar", re-learning starts and your spam filter gets smarter. Repeat the steps(8-9) until no errors are found. ■Mail Rules: There are 4 conditional fields for mail rules --- sender, subject, message, compound. Mail rules are only applied for 'INBOX'. To edit or create a mail rule, tap 'Edit' button on the Mailbox list. The selection menu appears, choose 'Rule'. Mail rules for ‘Sender’ will appear. Tap a Tab bar to switch a view . ■Other usage: Please visit support page. http://www.seimitsusakufu.com/iOS/mailapps/en/support.html ■Support: To get a further support , contact through the following mail address. support_seimitsu@jcom.home.ne.jp

About

Exo

Securely store and share files with decentralized, encrypted storage. Organize, preview, and rename files effortlessly with an intuitive interface. Enjoy lightning-fast access and enhanced privacy with no central servers.

Highlights
  • Decentralized encrypted storage
  • Automatic file organization
  • Instant file previews
  • Secure file sharing
  • Edit file names
  • Lightning-fast access
Features
Read full description

- Decentralized Storage: Your files are encrypted and securely stored across a global, distributed network, ensuring privacy and resilience. - Automatic File Organization: Smart categorization automatically organizes files into folders like Images, Videos, PDFs, and more for effortless management. - Instant File Previews: Quickly view images, documents, and other file types without downloading, making navigation seamless. - Secure File Sharing: Generate unique, secure share links for quick and protected file sharing. - Edit File Names: Rename files easily while preserving their extensions, ensuring clarity and consistency. - Lightning-Fast Access: Enjoy quick and reliable access to your files anytime, anywhere. - Enhanced Privacy: Only you have access to your files—no central servers involved. - Intuitive Interface: A clean and modern design ensures ease of use for everyone.

Screenshots

MailCat4 screens
Exo3 screens

Verdict

The call

The clearest difference is price: Exo at Free against MailCat's $3.99. Exo also leads on rating (5.0 vs 1.0). MailCat's advantage is update cadence (every 4 months vs every 15 months). On ratings volume, ads, in-app purchases and device support there is nothing between them.

Scored on Price · Rating · Positive reviews · Number of ratings · Update frequency · Ads · In-app purchases · Monetization · Best chart rank · Devices · Requires iOS

CostPrice · In-app purchases · Ads · Monetization

Exo is free to download; MailCat costs $3.99 up front. Neither carries in-app purchases, so what you see is what you pay.

ReceptionRating · Positive reviews · Number of ratings

Exo holds the better App Store score, 5.0 against 1.0. Both are backed by a comparable volume of ratings — 1 and 1 respectively.

UpkeepUpdate frequency

MailCat ships an update every 4 months, Exo every 15 months. The most recent releases landed on November 1, 2026 and November 3, 2026 respectively.

Scorecard4 real differences · 6 level
MailCat versus Exo: the parameters behind the verdict, then further details
ParameterMailCatExo
Price$3.99Free — better
Rating1.0 (1 ratings)5.0 (1 ratings) — better
Positive reviews13.0% of reviews—
Number of ratings11
Update frequencyEvery 4 months — betterEvery 15 months
AdsNoNo
In-app purchasesNoNo
MonetizationPaidFree — better
DevicesiPhone, iPadiPhone, iPad, iPod — better
Requires iOS16.615.1 — better
Further details — not scored
Size4 MB21 MB
Age rating4+4+
DeveloperSeimitsusakufu LLCJaydon Lynch

Customer experience

MailCat

All ratings1 ratings
Positive0.0%
Neutral0.0%
Negative100.0%
Written reviews23 reviews
Positive13.0%
Neutral13.0%
Negative73.9%

Exo

All ratings1 ratings
Positive100.0%
Neutral0.0%
Negative0.0%

In-app purchases

None

MailCat

No in-app purchases

None

Exo

No in-app purchases

Questions

Is MailCat free?
MailCat costs $3.99, with no in-app purchases.
Is Exo free?
Exo is free to download, with no in-app purchases.
Which has better reviews, MailCat or Exo?
Exo is rated higher. MailCat averages 1.0 out of 5 from 1 ratings, while Exo averages 5.0 from 1 ratings.
Do MailCat or Exo have ads?
Neither MailCat nor Exo shows ads.
Which is updated more often, MailCat or Exo?
MailCat ships an update every 4 months, and Exo every 15 months. Most recently, MailCat was updated on November 1, 2026 and Exo on November 3, 2026.

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