tinyapps.org / blog

Exporting/archiving email from Mail.app #

Michael Tsai has hosted a long-running discussion on data loss in Mail.app starting in Catalina and continuing unabated through Big Sur and Monterey (I have settled on only moving messages from IMAP servers to local storage via Thunderbird).

Further, Mail's built-in export (and import) methods suffer from various limitations and bugs; the following tests were run under macOS 12.4 and Mail 16.0 (3696.100.31):

1. Mailbox → Export Mailbox...

1. Creates a single MBOX file containing all messages (actually a slightly nonstandard folder with the mbox file named "mbox" and another file named "table_of_contents").

2. Pro: Successfully exported all messages.

3. Con: Attempting to import such MBOX files (containing any significant number of messages) back into Mail generally fails with the following error: Some messages could not be imported. The partially imported mailboxes are located in the mailbox named "Import" in the mailboxes list.

4. While Mail displayed a count of 4611 messages for the mailbox, 4618 were shown in Claws Mail and Thunderbird after import.

2. Click and drag multiple messages from Mail to Finder

1. Creates a single EML file per message (converting from Mail's native EMLX format, which stores attachments separately) as opposed to MBOX's monolithic single file format.

2. Pro: Works on even large numbers of messages (tested on a selection of over 10,000 - see below).

3. Con: Silently fails to export messages with subject lines 252 characters or longer.

4. When performed on the aforementioned mailbox (which Mail showed as containing 4611 messages while the exported MBOX file was reported to hold 4618), only 4600 messages were exported. The missing messages all had subject lines over 251 characters in length. This was verified by getting a list of all subjects in the mailbox via AppleScript (which also returned 4618 instead of 4611):
   
tell application "Mail" to get the subject of every message of mailbox "foo"
set subjectList to result
set AppleScript's text item delimiters to "\n"
set subject1PerLine to subjectList as string
get subject1PerLine

   then locating those containing 252 or more characters: grep '.\{252\}' subjects.txt. Sure enough, the difference was exactly 18.

5. Mail reported 10,663 messages in another mailbox; however, clicking and dragging them to a folder in Finder resulted in 10,672 EML files, indicating once again that Mail has a hard time keeping track of messages.

3. AppleScript

1. Tom Floeren's 2017 "Export Selected Mail Messages" AppleScript still runs under Monterey, exporting highlighted messages to EML files.

2. Pro: Truncates subjects/filenames over 180 characters to avoid the con described in 2c.

3. Con: 31 messages were missing from the export after the script terminated with Script Error: AppleEvent timed out. Happily, this was easily rectified by adding with timeout of 3600 seconds above repeat with i from 1 to count of msgSubjects and end timeout below end repeat; afterwards, all messages exported successfully.

4. As in 1d and 2d above, 4618 messages were exported from the mailbox which Mail had reported as containing 4611 messages. As a final test, ran this simple AppleScript oneliner to get the number of messages in the mailbox: tell application "Mail" to get the count of messages of mailbox "foo"; the result was 4618.

5. Updated script:
   # Name: Export Selected Mail Messages # Description: Exports selected mail messages from Apple’s Mail app as .eml # Web page: <http://dflect.net/bulk-export-selected-mails-from-apple-mail/> # Author: Tom Floeren <tom@dflect.net> # Created: 2017-02 # Last modified: 2022-06-14 (by Miles Wolbe to resolve "AppleEvent timed out"; # see https://tinyapps.org/blog/202206140700_mail-app-export.html for details) # Version: 1.0.1 # # Copyright © 201X-2017 Thomas Floeren # # Permission to use, copy, modify, and/or distribute this software for any # purpose with or without fee is hereby granted, provided that the above # copyright notice and this permission notice appear in all copies. # # THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES WITH # REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY # AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY SPECIAL, DIRECT, # INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM # LOSS OF USE, DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR # OTHER TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR # PERFORMANCE OF THIS SOFTWARE. use AppleScript version "2.4" -- Yosemite (10.10) or later use scripting additions set exportDestination to missing value # If you like, set your export folder here (HFS notation = separate path components with a colon “:” + trailing “:”) # If you don’t set a folder here the script will ask you each time for the destination. # Some examples: --set exportDestination to (path to desktop) & "Exported Mails:" as text --set exportDestination to (path to documents folder) & "My Mails:" as text --set exportDestination to (path to home folder) & "My Backup Folder:Exported Mail Messages:" as text set fieldSeparator to space set msgSubjects to {} set msgDates to {} set msgSenders to {} set msgSources to {} set msgCount to 0 # Ask for destination (if no path is set at the beginning of the script) if exportDestination is missing value then set exportDestination to chooseFolder() as text # Start stop watch set timeStart to current date # Grab the messages tell application "Mail" set selMsgs to the selected messages of the front message viewer if selMsgs is missing value then my alertNoSelection() error number -128 end if repeat with theMsg in selMsgs set {end of msgSubjects, end of msgSenders, end of msgDates, end of msgSources} to {subject of theMsg, sender of theMsg, date received of theMsg, source of theMsg} end repeat end tell # Write messages to file with timeout of 3600 seconds repeat with i from 1 to count of msgSubjects set {theSender, theSubject, theDate, theSource} to {item i of msgSenders, item i of msgSubjects, item i of msgDates, item i of msgSources} set saveTID to AppleScript's text item delimiters # Format sender # Full email address --set AppleScript's text item delimiters to {"<", ">"} # Email address without TLD set AppleScript's text item delimiters to {"<", "."} set theSender to text item -2 of theSender # Format date/time as short ISO set AppleScript's text item delimiters to {""} set theDate to theDate as «class isot» as string set theDate to words 1 thru -2 of theDate as text set theDate to text 3 thru -1 of theDate # Format subject # ':' is the only forbidden character on macOS. You can add more characters if you want, for example '{".", "?", "/", "<", ">", "\", "|"}' set AppleScript's text item delimiters to {":"} set theSubject to every text item of theSubject set AppleScript's text item delimiters to {"-"} set theSubject to theSubject as text set AppleScript's text item delimiters to saveTID # Compose file name set msgFileName to theDate & fieldSeparator & theSender & fieldSeparator & theSubject # Limit file name length # Max is 255, but decomposed characters like ü, ä, é etc. count as two charcters (UTF-8 NFD!); so we better have some margin. if (count of msgFileName) > 180 then set msgFileName to text 1 thru 180 of msgFileName set msgFileName to msgFileName & ".eml" # Save to file try set newFile to (open for access file (exportDestination & msgFileName) with write permission) on error errMsg number errNum if errNum is -43 then alertDestination(exportDestination, errNum, errMsg) else if errNum is -1410 then alertNameLength(msgFileName, errNum, errMsg) else alertOther(errNum, errMsg) end if error number -128 end try write theSource to newFile close access newFile set msgCount to msgCount + 1 end repeat end timeout # Read stop watch set timeElapsed to (current date) - timeStart # Display stats display alert "Completed" message "Exported " & msgCount & " message(s) in " & timeElapsed & " seconds to “" & (POSIX path of exportDestination) & "”." as informational ------------------------------------------------------------------------ # Handlers on chooseFolder() tell application (path to frontmost application as text) set dest to (choose folder with prompt "Pick a folder to export your mails to:") end tell return dest end chooseFolder on alertNoSelection() display alert "No Message Selected!" message "Select one or more messages in the messages list and run the script again." buttons {"Got it!"} end alertNoSelection on alertDestination(dest, eNum, eMsg) # -43 display alert "Destination folder missing or not accessible" message "Please check the folder path you have set at the beginning of the script or check the write permissions of the destination folder:" & return & return & dest & return & return & "# Error number:" & return & eNum & return & return & "# Error message:" & return & eMsg as critical end alertDestination on alertNameLength(fName, eNum, eMsg) # -1410 display alert "File name too long" message "Because of a very long Subject line the file name of this email message is too long:" & return & return & fName & return & return & "Please lower the file name length limit in the script." & return & return & "# Error number:" & return & eNum & return & return & "# Error message:" & return & eMsg as critical end alertNameLength on alertOther(eNum, eMsg) display alert "An error has occurred" message "The following error has occurred:" & return & return & "# Error number:" & return & eNum & return & return & "# Error message:" & return & eMsg as critical end alertOther

4. partial-emlx-converter

1. Open source script that "converts .emlx and .partial.emlx files written by Apple's Mail.app into fully self-contained, 'stand alone' .eml files."

2. The author, Philipp Katz, relates that "one of my IMAP mailboxes went out of service and I was not able to copy all the messages to a different account with Mail.app, even though all mails and attachments were there (see here for the story). That’s why I created this script."

3. Pro: Successfully converted all 4618 messages in test mailbox to EML format.

4. Con: Not native.

/mac | Jun 14, 2022

Virtualizing Linux, macOS, and Windows ARM64 versions on an M1 Mac #

/mac | Jun 11, 2022

Workflow for scanning/digitizing books #

1. Scan with smartphone or tablet to JPG via vFlat Scan (Android | iOS)
2. Clean up scans and convert to B&W TIF via ScanTailor Advanced or ScanTailor Universal
3. OCR and convert to PDF via Adobe Acrobat

/misc | May 20, 2022

Restore macOS Contacts from Time Machine backup #

or any other backup of ~"/Library/Application Support/AddressBook/".

Caution

No consideration is given here to iCloud Contacts sync (though thermo2's 20-step procedure is reproduced below without prejudice). Back up, back up, back up and understand what you are doing. Contacts.app needs to be closed before attempting all methods but the first.

Method 1

Open Contacts.app then "Enter Time Machine" from menu bar icon to restore (H/T). Note that the "Browse Other Backup Disks..." option accessed by Option-clicking the Time Machine menu bar icon really means "Browse Other Backup Disks for the current device". (UPDATE: Michael Tsai reports that this method does not work in Monterey; further, he shared that Time Machine restores in apps other than Finder have not worked for him since around Mojave.)

Method 2

Replace ~"/Library/Application Support/AddressBook/" folder with backup copy of same (tested successfully in High Sierra, Mojave, Catalina, Big Sur, and Monterey).

Method 3

Add .abbu extension to backup copy of ~"/Library/Application Support/AddressBook/" then double click to import (tested successfully in modern macOS versions; similar to above method, but might make importing recovered data simpler for end users).

Method 4

Replace ~"/Library/Application Support/AddressBook/AddressBook-v22.abcddb" with backup copy of same (tested successfully in Lion, but failed in modern macOS versions).

Method 5

1. Delete contents of ~"/Library/Application Support/AddressBook/".

2. Paste the Metadata folder containing .abcdp files (found at either ~"/Library/Application Support/AddressBook/Metadata/" or ~"/Library/Application Support/AddressBook/Sources/UUID/Metadata/") from backup copy into ~"/Library/Application Support/AddressBook/".

3. Launch Contacts.app; it will recreate AddressBook-v22.abcddb from the .abcdp files in Metadata/ (tested successfully in High Sierra and Mojave, even for Metadata folders created under newer versions of macOS (which is fortunate, as the process failed in Catalina, Big Sur, and Monterey; after exporting a Contacts Archive from Mojave, it was successfully restored to Big Sur, though logging off and on was required for the contacts to appear)).

Related

• Address Book File Locations (2009)

• contact_reaper.py: "A small program that grabs the information of every contact on a user's mac" (pulls from .abcdp files in ~"/Library/Application Support/AddressBook/Sources/UUID/Metadata/") 💾

• SQLite:

  • alexantd's answer to How to access data from a Mac Contacts backup: a .abbu file

  • How to Export a Mac's Contacts or Address Book

  • Synoli's reply to software problem: retrieve contacts data from Time Machine

  • sqlite3 and Address Book.app from the Command Line

  • Database schema

• thermo2's iCloud workaround (linked from Time Machine - Frequently Asked Questions: 15c. Viewing or Restoring Contacts / Address Book: "If you're using iCloud, the procedure ... will not 'stick' since the cloud contains the 'master' copy, as soon as you connect to it, anything you restored from your backups will be replaced with the contents from the cloud. For a workaround, see this discussion post."):

  1. If using iCloud, uncheck Contacts box in System Preferences>iCloud
  2. Quit Address Book
  3. Restore Address Book folder in User/Library/Application Support to previous version with Time Machine
  4. Trash all Address Book preferences in User Library/Preferences
  5. Log Out/In or Restart
  6. Start Address Book and verify desired address book version is now available
  7. If not using iCloud you are done, otherwise you need to create new Address Book Folder with current file dates that contains desired previous data
  8. First Go to Web version of iCloud Contacts and erase all contacts
  9. From Address Book Export vCard with All Contacts
  10. Export vCard for each manually defined group
  11. Quit Address Book
  12. Trash Address Book folder in User/Library/Application Support
  13. Trash all Address Book preferences in User Library/Preferences
  14. Log Out/In or Restart
  15. Start Address Book and Import vCard with All Contacts
  16. Import vCard for each defined group one at a time and:
  17. Check review duplicates and keep new
  18. Select Last Import for each group and manually assign to Group Name
  19. Re-Check Contacts box in System Preferences>iCloud
  20. New address book should populate to iCloud and other devices

/mac | May 19, 2022

Twitter feed shutting down #

/misc | Apr 26, 2022

Imaging and recovering data from floppy disks #

DOS

• VGA-COPY/386 6.25: "World-renowned utility for copying and formatting floppy disks."

  • Archived download
  • Background information
  • Last blog post
  • Attempting to Repair Bad Sectors on Damaged Floppy Disks in MS-DOS: "VGA Copy is particularly useful when bad sectors cannot be repaired."
  • Comment attributed to 030 Datenrettung Berlin GmbH: "The best software to recover / copy floppies I know is VGAcopy/386..."

• ImageDisk 1.18 "is a program to read entire diskette images into files (type .IMD), and to recreate a copy of the diskette from that image. A detailed analysis is performed on the diskette, and information about the formatting is recorded in the image file. This allows ImageDisk to work with virtually any soft-sectored diskette format that is compatible with the PC's type 765 floppy diskette controller and drives."

• DiskImg: "Read/write complete (physical/logical) disk to/from file."

• SpinRite: "Everything SpinRite does for hard disk drives also works on floppy diskettes of any size and density."

  • Spiceworks reviews
  • Does SpinRite do what it claims to do?
  • Spinrite 6: An overdue review

Linux

• cat:

  • cat /dev/fd0 > floppy.img

• dd:

  • dd if=/dev/fd0 of=floppy.img conv=notrunc

• ddrescue:

  • From the manual:

    • "-c sectors Number of sectors to copy at a time.…The number of sectors per track (18 or 9) is a good value for floppies." [emphasis added]
    • "-d Use direct disc access…to read from infile, bypassing the kernel cache.…Sector size must be correctly set for this to work.…"

  • 1.44MB floppy: ddrescue -b 512 -c 18 -d /dev/fd0 floppy.img floppy.map

  • DOS floppy imaging/recovering examples from Archive Team (source)

• dumpfloppy "is a suite of tools for reading floppy disks in arbitrary formats supported by the PC floppy controller, and for working with the resulting image files. For image files, it uses the IMD format defined by Dave Dunfield's ImageDisk. You can capture an image with dumpfloppy and then write it back with ImageDisk, or use the dumpfloppy tools to examine or extract an ImageDisk file."

  • No compiling instructions included; found them in BitCurator's bootstrap.sh: aclocal --force && autoconf -f && automake --add-missing && ./configure && make
    (apt install automake if missing. Also encountered "make: Warning: File 'Makefile.am' has modification time 63026 s in the future" error; resolved thusly: find -type f -exec touch {} + && make clean && make)

  • Old fork: "Dumpfloppy dumps floppy disk images to files. Unlike ddrescue, dd_rescue or safecopy, it allows storing multiple CRC-failed reads to get the best possible data from failing floppy disks. Original by Adam Sampson."

• safecopy "is a data recovery tool which tries to extract as much data as possible from a problematic (i.e. damaged sectors) source - like floppy drives, hard disk partitions, CDs, tape devices, ..., where other tools like dd would fail due to I/O errors."

Windows

• BadCopy Pro 4.10: "BadCopy Pro is the leading data recovery software for flash drive, USB drive, CD, DVD, memory card, floppy disk and other removable disks. BadCopy Pro can effectively recover and rescue corrupted or lost data from damaged, unreadable, formatted or defective disks. It works with Microsoft Windows 98/2000/XP/Vista/7/8/10."

• Roadkil's Unstoppable Copier 5.2: "Recovers files from disks with physical damage. Allows you to copy files from disks with problems such as bad sectors, scratches or that just give errors when reading data. The program will attempt to recover every readable piece of a file and put the pieces together. Using this method most types of files can be made useable even if some parts of the file were not recoverable in the end."

• WinImage 10.0: "WinImage is a fully-fledged disk-imaging suite for easy creation, reading and editing of many image formats and fileystems, including DMF, VHD, FAT, ISO, NTFS and Linux. The disk image is an exact copy of a physical disk (floppy, CD-ROM, hard disk, USB, VHD disk, etc.) or a partition that preserves the original structure. With WinImage in place, you can recreate the disk image on the hard drive or other media, view its content, extract image-based files, add new files and directories, change the format, and defragment the image. All this and more is delivered in one intuitive user interface that enables imaging right out of the box."

• WinDiskImg: "Read/write complete (physical/logical) disk to/from file."

• Roadkil's Disk Image: "Creates and writes disk images files to hard and floppy disks."

Hardware

• Greaseweazle: "Tools for accessing a floppy drive at the raw flux level"

  • FluxMyFluffyFloppy
  • GreaseweazleGUI

• KryoFlux "is a USB-based device designed specifically for the reliability and precision needed to acquire reliable low-level reads suitable for software preservation."

  • Archivists Guide to KryoFlux
  • The KryoFlux Floppy Controller: A Magnetic Media Miracle
  • Project Kryoflux – Part 2: Why Bother with it?
  • Can't Copy that Floppy? KryoFlux Can! feat. Unistat V4.53
  • Jason Scott is not exactly a KryoFlux fan

• Archive Team's Rescuing Floppy Disks offers a comprehensive hardware guide.

Related

• Floppy Disk Useful Storage Space: "1.44MB Floppy - 80 tracks x 18 sectors x 2 sides x 512 bytes per sector = 1,474,560 bytes"

• Maxiumum recovery of data from old floppy discs with padded bad sectors and multiple passes

• Mounting a disk image using the loop device

• Floppy Disk Transfer: OmniFlop

• Floppy disk imaging - what program to use?

• Recovering Data From Floppies With Errors

• Recovering "lost" treasure-filled floppy discs with an oscilloscope

• Preserving a floppy disk with a logic analyzer and a serial cable

• What is the little twist in this floppy ribbon cable for?

• From Adafruit Floppy's FAQ:

  Did you know there are USB Floppy Drives for $10 on Amazon?
  Yes, we are aware. These are recycled laptop floppy drives with a controller chip that presents a mass storage interface to the sectors on disk. They are great for basic access to 1.44MB IBM PC MFM-formatted diskettes. They will not work for GCR formatted diskettes (we know because we tried) and may not work with non-FAT formatted diskettes (we don't have any but the controller chip is very specialized and may freak out). USB floppy drive controllers will not get you flux-level readings, and can't cope with damaged diskettes to read sector data that does not pass CRC to perform data recovery. They are also, of course, no good with 5.25" floppy diskettes.

  Why do you need a flux level reading of disks???
  Flux level readings are essential for data recovery, restoration, archiving of damaged or copy-protected floppies.

/misc | Apr 17, 2022

macOS: Find file extensions associated with an app #

Shortcat would not import its license file (named "shortcat-license") through the "Add License" button (where the file appeared as greyed out), via drag and drop into the License window, or via drag and drop onto Shortcat.app.

Resolved by finding which file extension Shortcat was associated with in /Applications/Shortcat.app/Contents/Info.plist → CFBundleTypeExtensions^*:

<key>CFBundleTypeExtensions</key>
<array>
    <string>shortcat-license</string>
</array>

Just needed to add any filename and a dot before "shortcat-license", which turned out to be an extension rather than a filename.

^* From the CFBundleDocumentTypes documentation:

Key: CFBundleTypeExtensions
Xcode name: "Document Extensions"
Description: This key contains an array of strings. Each string contains a filename extension (minus the leading period) to map to this document type. To open documents with any extension, specify an extension with a single asterisk "*". (In OS X v10.4, this key is ignored if the LSItemContentTypes key is present.) Deprecated in OS X v10.5.

/mac | Mar 25, 2022

Get macOS installers (app, dmg, iso, pkg) and firmware (ipsw) #

with the free and open source MIST - macOS Installer Super Tool:

% mist list
┌──────────────────┐
│ INPUT VALIDATION │
└──────────────────┘
  ├─ Kind will be 'installer'...
  ├─ Include betas in search results will be 'false'...
  ├─ Output type will be 'ascii'...
┌────────┐
│ SEARCH │
└────────┘
  ├─ Searching for macOS Installer versions...
  └─ Found 23 macOS Installer(s) available for download

Identifier │ Name              │ Version │ Build   │ Size     │ Date
───────────┼───────────────────┼─────────┼─────────┼──────────┼───────────
071-08758  │ macOS Monterey    │ 12.3    │ 21E230  │ 12.23 GB │ 2022-03-14
002-66265  │ macOS Monterey    │ 12.2.1  │ 21D62   │ 12.16 GB │ 2022-02-17
002-57041  │ macOS Monterey    │ 12.2    │ 21D49   │ 12.16 GB │ 2022-01-26
002-42435  │ macOS Monterey    │ 12.1    │ 21C52   │ 12.16 GB │ 2022-01-14
002-23774  │ macOS Monterey    │ 12.0.1  │ 21A559  │ 12.13 GB │ 2021-12-01
002-77154  │ macOS Big Sur     │ 11.6.5  │ 20G527  │ 12.42 GB │ 2022-03-14
002-65695  │ macOS Big Sur     │ 11.6.4  │ 20G417  │ 12.45 GB │ 2022-02-17
002-57023  │ macOS Big Sur     │ 11.6.3  │ 20G415  │ 12.44 GB │ 2022-01-26
002-42341  │ macOS Big Sur     │ 11.6.2  │ 20G314  │ 12.44 GB │ 2022-01-14
002-23589  │ macOS Big Sur     │ 11.6.1  │ 20G224  │ 12.43 GB │ 2021-12-01
071-78704  │ macOS Big Sur     │ 11.5.2  │ 20G95   │ 12.45 GB │ 2021-08-18
001-68446  │ macOS Catalina    │ 10.15.7 │ 19H15   │ 08.75 GB │ 2020-11-11
001-57224  │ macOS Catalina    │ 10.15.7 │ 19H4    │ 08.75 GB │ 2020-10-27
001-51042  │ macOS Catalina    │ 10.15.7 │ 19H2    │ 08.75 GB │ 2020-09-24
001-36801  │ macOS Catalina    │ 10.15.6 │ 19G2021 │ 08.75 GB │ 2020-08-12
001-36735  │ macOS Catalina    │ 10.15.6 │ 19G2006 │ 08.75 GB │ 2020-08-06
001-15219  │ macOS Catalina    │ 10.15.5 │ 19F2200 │ 08.74 GB │ 2020-06-15
001-04366  │ macOS Catalina    │ 10.15.4 │ 19E2269 │ 08.75 GB │ 2020-05-04
061-86291  │ macOS Catalina    │ 10.15.3 │ 19D2064 │ 08.69 GB │ 2020-03-23
061-26589  │ macOS Mojave      │ 10.14.6 │ 18G103  │ 06.52 GB │ 2019-10-14
061-26578  │ macOS Mojave      │ 10.14.5 │ 18F2059 │ 06.52 GB │ 2019-10-14
041-88800  │ macOS Mojave      │ 10.14.4 │ 18E2034 │ 06.53 GB │ 2019-10-23
041-91758  │ macOS High Sierra │ 10.13.6 │ 17G66   │ 05.71 GB │ 2019-10-19

/mac | Mar 24, 2022

macOS: Mount exFAT partitions created in Windows #

0. Issue

An 8TB USB HDD formatted as exFAT in Windows 10 (using the default settings) would not mount in macOS 12.

Disk Utility showed the exFAT partition greyed out. Right clicking it and selecting "Mount" returned:

Could not mount “8TB”. (com.apple.DiskManagement.disenter error 49223.)

Terminal fared no better:

   % sudo mount -t exfat /dev/disk2s2 ~/mnt
   mount_exfat: /dev/disk2s2 on /Users/user/mnt: Invalid argument
   mount: /Users/user/mnt failed with 71

1. Cause

Seagate's Disk Utility Errors and Questions for macOS 10.11 and higher explains:

Error Message - com.apple.DiskManagement.disenter error 49223
This error message has been seen with drives formatted ExFAT. When using a drive between macOS and Windows, drives should always be formatted on macOS because not all Windows allocation unit sizes (block sizes) are supported by macOS. An unsupported allocation unit size will keep the drive from mounting. This error will be displayed when trying to mount the drive manually with Disk Utility. If you are using this drive between macOS and Windows then back up any important data on the drive and reformat the drive ExFAT on macOS.

2. Solution

Rather than reformatting, exFAT for FUSE (which supports clusters up to 32 MB) was used to successfully mount the partition in macOS:

% sudo /usr/local/sbin/mount.exfat-fuse /dev/disk2s2 ~/mnt

3. Prevention

Finding only incomplete or incorrect guidance online, I decided to test every allocation unit size displayed in the Windows format GUI:

2048 bytes
4096 bytes
8192 bytes
16 kilobytes
32 kilobytes
64 kilobytes
128 kilobytes
256 kilobytes
512 kilobytes
1024 kilobytes
2048 kilobytes
4096 kilobytes
8192 kilobytes
16384 kilobytes
32768 kilobytes

(as well as the two smaller options, 512 and 1024 bytes, offered in the CLI), prepping partitions via the command prompt, e.g., C:\>format Z: /fs:exfat /v:test /q /a:128k .

macOS was able to natively mount exFAT partitions with cluster sizes from 512 bytes to 1024 KB, but not from 2048 KB through 32768 KB.

4. Notes

• Retrieve cluster size:

  • Windows:
    
    PS C:\> Get-Volume Z | Format-List AllocationUnitSize
    ...
    AllocationUnitSize : 32768

  • macOS:
    
    % diskutil disk2s2 | grep Allocation
    ...
    Allocation Block Size: 32768 Bytes
    

• What Is the Best Allocation Unit Size for exFAT & How to Reset It:

  [I]f the size of the files you want to store on the drive is large, then a large cluster size is recommended, which will increase the data read-write speed. If you plan to store lots of small files, it is advisable to set a small cluster size, which can improve the disk space utilization.

• Microsoft: Default cluster size for NTFS, FAT, and exFAT (Only covers Windows XP–7, and sizes do not match those assigned by Windows 10; for example, an 8TB exFAT partition was assigned 2048 KB clusters rather than the stated 128 KB.)

• macOS: Can't mount exFAT External Drive

/mac | Mar 04, 2022

3 cross-platform email tools #

• imap-backup: "Backup GMail (or other IMAP) accounts to disk." Saves to mbox. Actively maintained. Ruby. HN discussion.

• Postsack: "A high level visual overview of swaths of email." Think GrandPerspective for email. Rust.

• NodemailerApp: "App includes local SMTP and POP3 servers, a sendmail replacement, catchall email domain service, AMP4Email renderer and it imports emails from EML files, EMLX files, large MBOX files from Gmail takeout, Maildir folders and Postfix queue files for inspection and preview. Ever wanted to view the actual HTML source of a nicely designed email instead of some garbled rfc822 text? Just open the HTML tab of an email to see it." [emphasis added] Electron.

/misc | Jan 10, 2022

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