■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
more Corrections are made to ensure compatibility with iOS 26.
1.6.0 2025-11-25
*Improvement & bug fix
1. Measures to cope with iO16
Bugs to be expected under iOS16 are fixed
2. iPhone notch support, until now the screen has been cut off in landscape mode.
1.5.9 2022-09-15
*Compatible with iOS15
*Bug fixes
1. Once it crashes, the app will not launch again.
2.When rule filtering is enabled, receiving mail might cause an infinite loop.
3.Flag processing when receiving mail might not be handled correctly.
4. Some icons are not displayed in dark mode.
5. In mail search, if you enter a search string, delete the string, and then enter another string, the search result will be wrong.
6.When viewing a mail displayed by mail search, if the mail is an HTML mail with embedded external images, the mail will not be displayed correctly.
1.5.8 2021-09-19
Improvement
1.Improved error handling when account reconnection fails.
Bug fixes
1. In some cases, fails to parse an email and crashes
2. Occasionally fails to display the subject of a mail
3. Occasionally crash on message download for multiple accounts.
4. Other bugs
1.5.7 2021-04-01
* Some of snap shots in the online help are not latest.
Improvement
1. Measures to cope with iO14
Bug fixes to be expected under iOS14
Bug fixes
1. Snippets might not be displayed with some mails
2. Fail to parse an email with a certain multipart form.
Others、the following features are suspended because of its instability.
1. Learning&Rule data sharing through iCloud
2. Section display in the mail list screen
3. Google OAuth2.0
1.5.6 2020-09-22
*** Notice:
From this version, the app doesn't support Google login(OAuth2.0) anymore.
The app is a spam filtering software.
Google doesn't allow any access to Gmail account through a spam filtering software.
Improvement
1. Measures to cope with iOS13
Bug fixes to be expected under iOS13
2. Mail search on a server
3. Browsing a message while downloading
4. Search field support upon mail searching
5. More precise progress view in case of lots of mail downloading
Bug fixes
1. *** Fix crashes
In case of "Wake up to refresh" is set, the app might crash at its wake-up.
2. Below iOS11, the progress view will not disappear when mail downloading finished.
1.5.5 2019-09-22
Improvement
1. The way of downloading the older mails is changed not to clatter the mail list view.
2. The keyboard keeps appearing after a rotation of a device.
Bug fixes
1. *** Fix a crash ****
If there are any mails without its mail body, the app checks to see if each mail really has no body or not through a separate thread. But this thread is not a safe thread. So it sometimes makes the app crash.
2. *** Fix a crash ****
When you tap an empty cell of the unified mailbox , the app crashes.
3. When you push up the mail view list at the bottom, it makes the app start downloading older mails.
But if the number of mails in a mailbox reaches the limit of its capacity, the app behaves weirdly,
4. In older iOS devices(with a poor cpu), the title bar clatters when a message view appears.
5. In the landscape mode, the keyboard hides an editing field at the account setting.
6. When you move from the bottom of the mail view list to the setting and go back to the mail view again, the app starts downloading older mails. The same phenomena occurs after a device’s rotation at the bottom of the mail view list.
7. The destination mailbox view appeared at moving mail messages is not supposed to be able to swipe.
But after swiping, the app starts behaving weirdly.
8. The mailbox view is not supposed to be able to swipe. But actually it can be swiped. It’s against the app’s specification.
9. Under the search results window of Monitor or Inbox, the following operations are not properly handled.
* swipe to blacklist
* swipe to spamdata
* swipe to route
* swipe to test spam
10. The layout of switch controls and textfield controls are not correct at the device’s rotation.
1.5.4 2019-02-05
Improvement
1. To change a message view, tap/swipe left or right the navigation bar instead of pulling down/up the view.
2. Add the counter of unread mails to the navigation bar of a message view.
Bug fixes
1. *** Fix a crash ****
App sometimes crashes when pulling down to refresh the mail list view where snippets of some mails are not gotten. It’s because that a thread to generate a snippet is not thread-safe.
2. A progress indicator is not displayed on the navigation bar when downloading mails(iOS12).
3. A menu in “Advanced setting” ( “Assume mails in inbox legitimate”) is truncated in iPhone SE.
4. In case of Google authentication expiration, although canceling a Google login, the account seems like connected. But trying to access a mail, the app will crash.
1.5.3 2019-01-03
Improvement
1. iOS12 support
Bug fixes
1. A navigation bar’s title may not be correctly displayed after moving, deleting messages.
2. If more than two google accounts are registered, the app may sometimes crash at its startup.
3. Rule check marks will be cleared at its startup after a crash.
1.5.2 2018-09-16
Improvement
1. Support for iPhone’s landscape mode
2. Timeout’s incident
Bug fixes
1. The right bar button retains itself after a iPad’s editing menu is canceled by tapping the outside area of the menu of the mailbox’s list.
2. Under iOS9, a mail view is pushed back twice after double-tapping a table cell of a mailbox list.
3. Under iOS9, a mailbox directory cannot be created.
4. A mailbox list view cannot be displayed properly under a certain condition.
5. Rule check marks might be cleared every time the inbox is reloaded.
6. Under iOS9, a back button of a iPad’s mail message view might be displayed.
7. An inline image might be treated like an external image when displaying a mail message.
8. Opening a URL in a mail message might fail when displaying a mail message.
9. It might access to a network while displaying a cached mail message.
10. Under iOS8, the app crashes during its start up.
11. The app crashes when a string is entered to a search window of a mail view other than unified or monitor.
12. In case of multiple accounts, a wrong destination list might be displayed when a rule is being registered by swiping a tableview cell of an inbox mail view list.
1.5.1 2018-05-23
Improvement
1.It’s changed into a universal app.
Bug fixes
1. The badge number of mails(or unread mails) may not be correct upon deleting, moving, unread/read operation
2. It may crash while swiping to register a rule to a unified mailbox where there is no real corresponding mailbox to an account.
3. It may fail in analyzing a mail with attached files
4. Section headers may be blurred after “push up to download” operation.
5. External images may not be completely blocked even if the external image block switch is set on.
6. Modified UTF-7 encode/decode routine doesn’t work properly so that the app may not deal with a certain mailbox name and cannot access it.
7. A simple rule cannot be moved into the compound rule section.
8. Fixes for the following crashes
*may crash upon rule filtering for the unified account when a rule is registered to the unified mailbox where there is no real corresponding mailbox to an account.
1.5.0 2018-04-25
Improvement
1. A mail rule registration by swiping right of the mail table cell.
2. Whitelist support
3. A rejected mail will be a candidate for spam rule filtering
4. Filtering results are indicated by not strings but icons.
(Some of other icons are updated for this)
5. The rule editing user interface is wholly updated.
6. A rule table cell supports a variable height.
7. Update a help.
Bug fixes
1. Fixes for the following crashes
*crashes while classifying the older mails.
*crashes while displaying a mail.
*crashes while trying a network error recovery
1.4.11 2018-01-08
1. The app ends up with infinite loop when a user pulls down to refresh a unified mailbox unless the mailbox has the corresponding mailbox of each account.
2. A compound rule parsing always fails if the compound rule includes the email address with a display name.
3. The rule view controller rotation behaves weirdly.
1.4.10 2017-09-25
Improvement
1. Advance setting menu is revised.
2. “Open url link” is supported.
3. “Access to an external site” warning.
(The warning can be suppressed by Advanced setting)
4. The search bar will hide itself.
Bug fixes
1. The previous version cannot run properly under iOS11
2. The app may crash at the App’s launching time immediately after the device’s power on.
3. The spam data specified by “swipe to spam data” cannot be removed from the learning data.
4. The extra large dynamic font makes the app’s screen clutter.
1.4.9 2017-09-19
Improvement
1. Spam test for each mail.
2. External images in HTML will be displayed with a HTML image blocking switch off
3. The network connectivity
Bug fixes
1. A spam filtering may not work at the App’s launching time immediately after the device’s power on.
2. When the messages’s moving failed due to a network error after a spam filtering, the spam filtering’s results would be serialized, and it would let the spam mails stay in Inbox.
3. Non-SSL connection would fail at the account setting.
4. The search bar is not displayed in the mail list
1.4.8 2017-08-18
Improvement
1. Support for the system mail flag—flagged
2. The position of the attachment icon
3. The display name of the sender email address can be specified as a mail rule.
Bug fixes
1. The app may become unstable when it goes back to the foreground state from the background state while receiving a large amount of mails.
2. The done button at the setting disappears after editing the complex rules of spam rules.
3. “Bad IMAP command” may display occasionally.
4. View’s rotation by the right swipe during the rule editing.
1.4.7 2017-05-23
Improvement
1. Google sign-in method is to be altered from April 20. The app is modified to cope with it.
2. In the complex rule editing mode, the moving around the views comes to be easily done by tapping the tool bar
below the screen.
3. In the complex rule editing mode, the swipe response is improved while moving around the views.
4. An recovery from a network error such as “timeout” or “idle too long” is improved.
Bug fixes
1. ”Couldn’t find the host xxx” may be displayed at the app’s startup.
2. The app may sometimes crash when it goes the foreground state immediately after the background state
by tapping the app icon immediately after clicking the Home button.
3. It may fail in paring an IMAP mail(it’s rare).
4. There is a spam rule(mail rule) which is never applied.
5. Other crashes.
1.4.6 2017-04-20
****
**** Support page’s URL will be changed to the following.
**** “http://members3.jcom.home.ne.jp/…” cannot be accessed since the end of January 2017
****
http://members3.jcom.home.ne.jp/support_seimitsu/mcat/en/support.html
―>
http://www.seimitsusakufu.com/iOS/mcat/
Improvement
1. “Wake up to refresh” feature is added. “Wake up to refresh” means the new mails are checked and loaded(with spam filtering) when the app wakes up from a sleep. But this setting can be set off at “Setting” page.
Bug fixes
1. The app may sometimes crash when it goes online from offline.
2. The view may not be able to rotate among Inbox(Monitor),Spam,Trash just after setting up an account.
3. A mail be rejected if the spam filter is effective and a spam rule matches with the mail message.
4. Other crashes.
1.4.5 2017-01-17
-Notice-
iCloud synchronization between devices is found to be unstable.
It's going to become unstable as time passes.
Fixes will come in the next major release.
Stop using iCloud is recommended for the time being.
Improvement
1. You can delete the account which is not connected.
Bug fixes
**1. The app becomes unresponsive when it starts up if the number of message in Inbox , the unified inbox or the monitor is less than 32.
**2. Even if the spam mail is re-specified as a legitimate mail and re-learned, it is not moved into Inbox. It’s one year old bug.
3. The snippets of mails in Inbox may not be redrawn.
4. Error “Bad IMAP command (UID STORE XXXX + FLAGS(\SEEN)” is often displayed.
5. Selection marks of mails is not redrawn once it is scrolled-in after scrolled-out.(only under iOS10)
6. The screen is black out when the app starts up in the airplane mode.(only under iOS10)
7. The app falls into the endless loop when you try to display the mail message in the airplane mode.
8. The app behaves strangely in the airplane mode
9. The mails message list doesn’t change while the account is changed within the single account.
10.The error may show up while you are pushing up to download.
11. When the attachment file is displayed, the back button is not displayed.
12. An attachment file may not be displayed properly.
13.The position of the command bar is left-sided on iPhone7plus,iPhone6Splus,iPhone6plus,
which appears by tapping ‘Edit’ button on the mail message list.
1.4.4 2016-10-04
-Notice-
iCloud synchronization between devices is found to be unstable.
It's going to become unstable as time passes.
Fixes will come in the next major release.
Stop using iCloud is recommended for the time being.
Improvement
1. Performance tuning
*It takes some time to exit from “Setting” page.
2. Adjusting progress position of Progress bar.
Progress position goes faster than actual processing position
3. Account management
Bug fixes
1. If “No Message” rule is in the spam rule, a mail with a message body may go to the spam box under a certain condition. This bug makes a legitimate mail move to a spam box.
2. If “Tap to edit” is in the spam rule, the checked marks in the message list will be cleared at every time of “pull to refresh”
3. If the message code is US-Ascii and a char whose sign bit is on is included, the message will be decoded as a null text.
4. The already filtered mails may be filtered again under a certain condition.
5. It doesn’t work properly under iOS6.
1.4.3 2016-09-21
-Notice-
iCloud synchronization(of SpamBlocker) between devices is found to be unstable.
It's going to become unstable as time passes.
Fixes will come in the next major release.
Stop using iCloud(of SpamBlocker) is recommended for the time being.
Improvement
1. Performance tuning
*The startup time is shortened
* The network related memory consumption is reduced.
2. Progress bar on the navigation bar while processing mails
It will prevent a user from judging that the app is being stalled when it is processing hundreds of mails.
3. Simplified UI of “pull down to refresh”
4. test under iOS10
Bug fixes
1. It may crash at the startup
1.4.2 2016-09-16
-Notice-
iCloud synchronization(of MailCat) between devices is found to be unstable.
It's going to become unstable as time passes.
Fixes will come in the next major release.
Stop using iCloud(of MailCat) is recommended for the time being.
Improvement
1. If “invalid_grant” error occurred at Google OAuth2.0 login , Google login authorization screen would appear.
2. The rejected/spammed mail can be swiped to blacklist. Previously it can’t be.
But the spammed mail is already in the spam mailbox, so only the mail address is registered in the blacklist.
Bug fixes
1. After “invalid_grant” error occurred at Google OAuth2.0 login, the pull to refresh will make the app crash.
2. The rejected mail cannot be rule-filtered.
3. A sender’s mail address is not correctly parsed. Sometime ‘)’ is added at the end of it.
4. If the size of dynamic font is changed, the layout of message list may be broken.
5. The already received mails may not be filtered by the specified number.
1.4.1 2016-07-18
-Notice-
iCloud synchronization(of MailCat) between devices is found to be unstable.
It's going to become unstable as time passes.
Fixes will come in the next major release.
Stop using iCloud(of MailCat) is recommended for the time being.
-Improvement-
1. Google OAuth2.0 login support( >= iOS7 )
-Bug fixes-
1. The learning data specified are not evaluated unless the spam filter switch is on
2. Crashes at the startup under iOS6
3. Crashes after tapping an account in the account list while failed in an account addition
4. Other crashes
1.4.0 2016-07-01
Bug fixes
1.A crash in reloading,learning,browsing mails
2.The shield icon doesn’t sync with the number of learning data
3.The selected status of account list doesn’t retain itself.
4.An alert will appear even if you choose “Don’t ask me again”
5.The mail search will fail in mailboxes other than unified mailbox.
6.”Pull to refresh” is allowed in the mail search mode
7.The App crashes in OS6 when it is terminated.
8.Right spaces in the mail list view
9.Switch control position in the Setting (iPhone)
10.Other occasional crashes
Improvement
1. the addition of launch image
1.3.7 2016-04-25
Bug fixes
1. A table cell does not return to the original position immediately after the swipe to delete.
2. The result of mail search may be wrongly displayed or it may crash with displaying the results.
3. Read/Unread operation in the mail list may not work from the second time.
4. The learning status still remains after the mail move operation.
1.3.5 2016-02-29
Corrections are made to ensure compatibility with iOS 26.
more Version 1.6.0 2025-11-25
Data Not Collected The developer does not collect any data from this app.
