Generate a Deterministic Synthetic Mail Corpus

Generates a reproducible corpus of synthetic RFC 822 messages to be stored in a mailbox with populate_sandbox, so that the package's searching, fetching, and decoding features can be demonstrated and tested without a real mail account – typically against the local Docker IMAP sandbox shipped in system.file("docker", package = "mRpostman").

sandbox_corpus(n = 200, seed = 3501)

Arguments

n

Number of messages to generate. Default is 200.

seed

An integer used as the RNG seed. The same n and seed always produce byte-identical messages. Default is 3501, after RFC 3501. The caller's RNG state is preserved.

Value

A list with two components: messages, a list of n character vectors (the lines of each RFC 822 message); and info, a data.frame with one row per message describing the features embedded in it (from, subject, date, is_utf8_body, is_large, has_attachment, attachment_type ("csv", "png", "pdf", or NA), is_reply, and the flags – seen, flagged – that populate_sandbox will set after appending).

Details

Message features are spread so that each capability of the package has matching messages to act upon: Date: headers spread over 2020 (SENTBEFORE/SENTSINCE/SENTON searches); a subset of large bodies (LARGER/SMALLER searches); accented subjects in MIME encoded-words and quoted-printable bodies (header and body decoding); CSV, PNG, and one-page PDF attachments – all generated deterministically in base R – some with repeated filenames (attachment listing, fetching, binary base64 decoding, and filename deduplication); and reply chains via In-Reply-To/References (SORT and THREAD).

See also

Other sandbox: enron_sandbox(), ingest_maildir(), populate_sandbox()

Examples

corpus <- sandbox_corpus(n = 5)
# the first synthetic message
cat(corpus$messages[[1]], sep = "\n")
#> From: Grace Holloway <grace.holloway@example.net>
#> To: Test User <testuser@sandbox.local>
#> Date: Sun, 26 Apr 2020 19:34:07 +0000
#> Message-ID: <msg0001@sandbox.local>
#> Subject: Invoice attached
#> MIME-Version: 1.0
#> Content-Type: text/plain; charset=utf-8
#> Content-Transfer-Encoding: quoted-printable
#> 
#> This supersedes the previous version sent last week.
#> 
#> Let me know if you need any further details before the meeting.
#> 
# features embedded in each message
corpus$info
#>   id                       from                       subject
#> 1  1 grace.holloway@example.net              Invoice attached
#> 2  2   alice.fontes@example.com           Relatório de vendas
#> 3  3   carla.mendes@example.com       Re: Travel arrangements
#> 4  4 grace.holloway@example.net Re: Server maintenance window
#> 5  5 grace.holloway@example.net     Server maintenance window
#>                              date is_utf8_body is_large has_attachment
#> 1 Sun, 26 Apr 2020 19:34:07 +0000        FALSE    FALSE          FALSE
#> 2 Thu, 04 Jun 2020 13:17:14 +0000         TRUE    FALSE          FALSE
#> 3 Sun, 28 Jun 2020 15:31:21 +0000        FALSE    FALSE           TRUE
#> 4 Wed, 16 Sep 2020 19:57:28 +0000        FALSE     TRUE          FALSE
#> 5 Fri, 25 Sep 2020 18:45:35 +0000        FALSE    FALSE           TRUE
#>   attachment_type is_reply  seen flagged
#> 1            <NA>    FALSE  TRUE   FALSE
#> 2            <NA>    FALSE  TRUE   FALSE
#> 3             csv     TRUE FALSE   FALSE
#> 4            <NA>     TRUE  TRUE    TRUE
#> 5             pdf    FALSE  TRUE    TRUE