--- title: "Inspect email files from the command line" url: https://recursiveai.org/onemail/cookbook/inspect-email-cli/ description: "Inspect .msg, .eml, .pst, mbox and winmail.dat files from the command line with the onemail .NET tool: sender, date, subject, attachments and defects, as text or JSON, and convert them to EML or mbox. OneMail.Cli 0.3.0-preview.2." version: "0.3.0-preview.2" --- # Inspect email files from the command line Install the `onemail` .NET tool and run `onemail inspect` on files or folders. Each message gets one line with its date, sender, subject, attachments and defects. Add `--json` for machine-readable output. It reads every format the library reads: `.eml`, `.msg`, `.pst`, `.ost`, mbox, Maildir, `winmail.dat`, Outlook Express `.dbx` and Outlook for Mac `.olm`. `onemail convert` writes them in another format. ```shell dotnet tool install -g RecursiveAI.OneMail.Cli --version 0.3.0-preview.2 onemail --version ``` ```text 0.3.0-preview.2 ``` The tool needs the .NET 10 runtime. The examples use public test files from Apache POI and Apache Tika: ```shell curl -LO https://raw.githubusercontent.com/apache/poi/REL_5_4_1/test-data/hsmf/attachment_test_msg.msg curl -LO https://raw.githubusercontent.com/apache/poi/REL_5_4_1/test-data/hmef/quick-winmail.dat curl -LO https://raw.githubusercontent.com/apache/tika/4.2.0/tika-parsers/tika-parsers-standard/tika-parsers-standard-modules/tika-parser-mail-module/src/test/resources/test-documents/complex.mbox curl -LO https://raw.githubusercontent.com/apache/tika/4.2.0/tika-parsers/tika-parsers-standard/tika-parsers-standard-modules/tika-parser-mail-module/src/test/resources/test-documents/testRFC822_multipart_attachments.eml ``` ## One file ```shell onemail inspect attachment_test_msg.msg ``` ```text attachment_test_msg.msg: Msg #0 2009-04-22T14:36:33Z from: Nicolas1 23456 subject: test pièce jointe 1 attachments: 2 (test-unicode.doc, pj1.txt) defects: 0 inspected 1 files/stores, 1 items, 2 attachments, 0 defects (0 ambiguities), 0 not readable ``` The last line is a summary, written to standard error. ## A folder, with attachment sizes `--sizes` adds each attachment’s decoded size in bytes. A folder is searched for every file it can read: ```shell onemail inspect --sizes . ``` ```text ./attachment_test_msg.msg: Msg #0 2009-04-22T14:36:33Z from: Nicolas1 23456 subject: test pièce jointe 1 attachments: 2 (test-unicode.doc 24064B, pj1.txt 89B) defects: 0 ./complex.mbox: Mbox #0 2009-06-01T04:26:31Z from: Jothi Padmanabhan subject: Re: question about when shuffle/sort start working attachments: 0 defects: 0 #1 2009-06-01T05:30:49Z from: Jianmin Woo subject: Re: question about when shuffle/sort start working attachments: 0 defects: 0 #2 2009-06-01T06:03:13Z from: Jothi Padmanabhan subject: Re: question about when shuffle/sort start working attachments: 0 defects: 0 ./quick-winmail.dat: Tnef #0 - from: - subject: - attachments: 5 (quick.doc 19968B, quick.html 428B, quick.pdf 18638B, quick.txt 235B, quick.xml 143B) defects: 1 ./testRFC822_multipart_attachments.eml: Eml #0 - from: Bugs Bunny subject: EML 1 attachments: 2 (Test TxtA.txt 33B, Test TxtB.txt 33B) defects: 0 inspected 4 files/stores, 6 items, 9 attachments, 1 defects (0 ambiguities), 0 not readable ``` ## Defects `--defects` lists each repair under its message, with the byte offset where it was found: ```shell onemail inspect --defects quick-winmail.dat ``` ```text quick-winmail.dat: Tnef #0 - from: - subject: - attachments: 5 (quick.doc, quick.html, quick.pdf, quick.txt, quick.xml) defects: 1 mapi:LowerLayerDefect @40 inspected 1 files/stores, 1 items, 5 attachments, 1 defects (0 ambiguities), 0 not readable ``` ## JSON `--json` writes one JSON object per line: one for each file or store, then one for each message. ```shell onemail inspect --json attachment_test_msg.msg ``` ```text {"type":"container","path":"attachment_test_msg.msg","format":"Msg"} {"type":"item","index":0,"kind":"Message","provenance":{"format":"Msg","location":"attachment_test_msg.msg","folder":null,"offset":0,"length":52224},"subject":"test pi\u00E8ce jointe 1","sender":[],"from":[{"name":"Nicolas1 23456","addr":"nicolas1.23456@free.fr"}],"to":[{"name":"\u0027nicolas1.23456@free.fr\u0027","addr":"nicolas1.23456@free.fr"}],"cc":[],"bcc":[],"replyTo":[],"date":{"utc":"2009-04-22T14:36:33Z","offsetMinutes":null,"source":"ClientSubmit"},"messageId":null,"inReplyTo":[],"references":[],"conversationTopic":"test pi\u00E8ce jointe 1","attachments":[{"name":"test-unicode.doc","type":"application/msword","contentId":null,"inline":false,"embedded":false},{"name":"pj1.txt","type":"text/plain","contentId":null,"inline":false,"embedded":false}],"defects":[]} ``` ## Convert `onemail convert` writes a file or a whole store in another format and lists what didn’t carry over. `--to` takes `eml`, `mbox`, `maildir`, `emlx`, `ics`, `vcf`, `jcal`, `jcard`, `xcal`, `xcard` or `tnef`: ```shell onemail convert --to eml attachment_test_msg.msg eml ``` ```text read 1 items, wrote 1 as Eml to eml, skipped 0, 1 with something that did not carry over Approximated DateSubSecondDropped (mapi) in 1 items, for example PidTagClientSubmitTime Approximated DefaultValueNotWritten (mapi) in 1 items, for example PidTagSensitivity Approximated HtmlFromRtf (mapi) in 1 items, for example PidTagRtfCompressed Dropped NoInternetMapping (mapi) in 1 items, for example PidTagCreationTime Dropped FlagsNotCarried (store) in 1 items, for example flags ``` The message is now `eml/000001-test-pi-ce-jointe-1.eml`. `onemail export` does the same for a whole store into a directory, and `--json` makes both machine-readable. The library call behind them: [Convert a PST file to mbox](https://recursiveai.org/onemail/cookbook/convert-pst-to-mbox/). ## Limits - **A preview.** 0.3.0-preview.2: the commands and their output can change before 1.0. - **No extract command.** To save attachments, use the library, as in [Extract attachments from email](https://recursiveai.org/onemail/cookbook/extract-attachments/). - **Not for calendar files.** `inspect` counts `.ics` and `.vcf` files as not readable; read them with [RecursiveAI.OneMail.Calendar](https://recursiveai.org/onemail/cookbook/read-ics-file/). The tool’s options: [Mail.Open and the read view](https://recursiveai.org/onemail/docs/shared-view/).