{emayili} is a package for sending emails from R. The design goals
are:
- works on all manner of SMTP servers and
- has minimal dependencies (or dependencies which are easily satisfied).
The package name is an adaption of the Zulu word for email, imeyili.
The documentation for {emayili} can be found
here.
Not that I pretend to have many stars on this project, but these plots are quite fun.
Get the stable version from CRAN.
install.packages("emayili")Or grab it directly from GitHub.
# Install from the master branch.
remotes::install_github("datawookie/emayili")
# Install from the development branch.
remotes::install_github("datawookie/emayili", ref = "dev")Load the library.
library(emayili)
packageVersion("emayili")[1] '0.7.4'
Create a message object.
email <- envelope()The message has class envelope.
class(email)[1] "envelope"
Add addresses for the sender and recipient.
email <- email %>%
from("[email protected]") %>%
to("[email protected]") %>%
cc("[email protected]")There are also bcc() and reply() functions for setting the Bcc and
Reply-To fields.
You can supply multiple addresses in a variety of formats:
- as a single comma-separated string
- as separate strings; or
- as a vector of strings.
envelope() %>% to("[email protected], [email protected], [email protected]")
envelope() %>% to("[email protected]", "[email protected]", "[email protected]")
envelope() %>% to(c("[email protected]", "[email protected]", "[email protected]"))Add a subject.
email <- email %>% subject("This is a plain text message!")Add a text body.
email <- email %>% text("Hello!")You can use html() to add an HTML body. It accepts either a vector of
characters or a tagList() from {htmltools}.
library(htmltools)
email <- email %>% html(
tagList(
h2("Hello"),
p("World!")
)
)Add an attachment.
email <- email %>% attachment("image.jpg")You can also create the message in a single command:
email <- envelope(
to = "[email protected]",
from = "[email protected]",
subject = "This is a plain text message!",
text = "Hello!"
)Simply printing a message displays the header information.
emailDate: Tue, 22 Oct 2024 03:44:31 GMT
X-Mailer: {emayili}-0.7.4
MIME-Version: 1.0
From: [email protected]
To: [email protected]
Cc: [email protected]
Subject: This is a plain text message!
You can identify emails which have been sent using {emayili} by the
presence of an X-Mailer header which includes both the package name
and version.
If you want to see the complete MIME object, just convert to a string.
You can also call the print() method and specify details = TRUE.
You can set the envelope.details option to assert that the details
should always be printed.
# Always print envelope details.
#
options(envelope.details = TRUE)By default the results returned by most of the methods are invisible.
You can make them visible via the envelope.invisible (default:
TRUE).
# Always show envelope.
#
options(envelope.invisible = FALSE)You can use {glue} syntax to interpolate content into the body of a
message.
name <- "Alice"
envelope() %>%
text("Hello {{name}}!")Date: Tue, 22 Oct 2024 03:44:31 GMT
X-Mailer: {emayili}-0.7.4
MIME-Version: 1.0
Content-Type: text/plain;
charset=utf-8;
format=flowed
Content-Disposition: inline
Content-Transfer-Encoding: 7bit
Content-MD5: nhjeY5ZYMzru+kSCGUzNKg==
Hello Alice!
You can render Markdown straight into a message.
Use either plain Markdown.
envelope() %>%
# Render plain Markdown from a character vector.
render(
"Check out [`{emayili}`](https://cran.r-project.org/package=emayili)."
)Date: Tue, 22 Oct 2024 03:44:31 GMT
X-Mailer: {emayili}-0.7.4
MIME-Version: 1.0
Content-Type: text/html;
charset=utf-8
Content-Disposition: inline
<html><body><p>Check out <a href="https://cran.r-project.org/package=emayili"><code>{emayili}</code></a>.</p></body></html>
Or R Markdown.
envelope() %>%
# Render R Markdown from a file.
render("message.Rmd")In both cases the function will accept either a file path or a character vector containing Markdown text.
Interpolation also works with render().
When you render an R Markdown document the resulting HTML includes CSS from three sources:
- Bootstrap
- highlightjs and
{rmarkdown}.
You can control which of these propagate to the message using the
include_css parameter which, by default, is set to
c("rmd", "bootstrap", "highlight").
🚨 Note: Gmail doesn’t like the Bootstrap CSS. If you want your
styling to work on Gmail you should set
include_css = c("rmd", "highlight").
You can insert extra CSS into your rendered messages.
envelope() %>%
render("message.Rmd", css_files = "extra.css")If you are having trouble getting this to work with Gmail then it might be worthwhile taking a look at their CSS support.
Adding an inline image to an HTML message is possible. There are two ways to achieve this.
1. Base64 Encoding
First you’ll need to Base64 encode the image.
img_base64 <- base64enc::base64encode("image.jpg")Then create the HTML message body.
html_body <- sprintf('<html><body><img src="data:image/jpeg;base64,%s"></body></html>', img_base64)And finally add it to the email.
email <- envelope() %>% html(html_body)Note: It’s important that you specify the appropriate media type
(image/jpeg for JPEG and image/png for PNG).
2. Using a CID
Unfortunately some mail clients (like Gmail) will not display Base64 encoded images. In this case using a CID is a working alternative.
First create the message body which references an image by CID.
html_body <- '<html><body><img src="cid:image"></body></html>'Then attach the image and specify the cid argument.
email <- envelope() %>%
html(html_body) %>%
attachment(path = "image.jpg", cid = "image")Create a SMTP server object.
smtp <- server(
host = "smtp.gmail.com",
port = 465,
username = "[email protected]",
password = "bd40ef6d4a9413de9c1318a65cbae5d7"
)It’s bad practice to include credentials in a script. A better approach
would be to keep the credentials in your .Renviron file.
GMAIL_USERNAME="[email protected]"
GMAIL_PASSWORD="bd40ef6d4a9413de9c1318a65cbae5d7"
You can then pull these variables into R using Sys.getenv() and then
create the server object.
smtp <- server(
host = "smtp.gmail.com",
port = 465,
username = Sys.getenv("GMAIL_USERNAME"),
password = Sys.getenv("GMAIL_PASSWORD")
)If you’re trying to send email with a host that uses the STARTTLS security protocol (like Gmail, Yahoo! or AOL), then it will most probably be blocked due to insufficient security. In order to circumvent this, you can grant access to less secure apps. See the links below for specifics:
Gmail has recently changed their authentication procedure. If you are having trouble connecting to the Gmail SMTP server then take a look at this.
Send the message.
smtp(email, verbose = TRUE)To see the guts of the message as passed to the SMTP server:
print(email, details = TRUE)Both transport-level encryption and end-to-end email encryption are supported. An SMTP connection can be initiated on port 465 (SMTPS, see RFC 8314) or 587 (SMTP-MSA, see RFC 6409), enabling transport-level encryption. Public-key cryptography (via GnuPG) can be used to sign and/or encrypt message contents for end-to-end encryption.
The following (draft) standards documents relate to emails:
- RFC 2822 — Internet Message Format
- RFC 5321 — Simple Mail Transfer Protocol
- RFC 5322 — Internet Message Format
- RFC 6854 — an update to RFC 5322.
There is a selection of other R packages which also send emails:
You can find the test coverage report at
Codecov. For development
purposes it’s more convenient to use the
{covr} package.
Generate a coverage report.
library(covr)
# Tests that are skipped on CRAN should still be included in coverage report.
#
Sys.setenv(NOT_CRAN = "true")
report()Calculate test coverage.
coverage <- package_coverage()Coverage statistics as a data frame.
as.data.frame(coverage)Show lines without coverage.
zero_coverage(coverage)Check spelling.
spelling::spell_check_package()Quick local checks.
devtools::check()Remote checks (take longer but more thorough).
devtools::check_win_devel()
# Check for a specific platform.
#
rhub::check(platform = "debian-gcc-devel")
rhub::check_on_windows(check_args = "--force-multiarch")
rhub::check_on_solaris()
# Check on a bunch of platforms.
#
rhub::check_for_cran()
# Check on important platforms.
#
rhub::check_for_cran(platforms = c(
"debian-gcc-release",
"ubuntu-gcc-release",
"macos-m1-bigsur-release",
"windows-x86_64-release",
NULL
))