Send an email via an R function using Mailgun

send_email_mailgun.R

#' Email a user a report is ready
#'
#' Requires an account at Mailgun: https://mailgun.com
#' Pre-verification can only send to a whitelist of emails you configure
#'
#' @param email Email to send to
#' @param mail_message Any extra info
#'
#' @return TRUE if successful email sent
#' @import httr
#' @export
sendEmail <- function(email = "[email protected]",
                      mail_message = "Hello"){

  url <- "https://api.mailgun.net/v3/sandbox5f2XXXXXXXa.mailgun.org/messages"
  ## username:password so api_key is all after the api:
  api_key <- "key-c5957XXXXXXXXXXXbb9cf8ce"
  the_body <-
    list(
      from="Mailgun Sandbox <[email protected]>",
      to=email,
      subject="Mailgun from R",
      text=mail_message
    )

  req <- httr::POST(url,
                    httr::authenticate("api", api_key),
                    encode = "form",
                    body = the_body)

  httr::stop_for_status(req)
  
  TRUE

}

For email attachments, modify above to include HTML files - see the API docs https://documentation.mailgun.com/en/latest/api-sending.html#sending

e.g.

 the_body <-
    list(
      from = from_name,
      to = email,
      subject = subject_line,
      html = html_string
    )

Hello!! Really enjoyed this function because I want to get rid of mailR::send.mail() that depends on rJava. But, how can I send attachments with PDFs, ggplots objects, CSVs, and simple HTML files as mailR does? Can you please share a reproducible example? Already have mi API credentials and is working just fine with simple texts.

I think it must have something to do with add_headers("Content-Type" = "multipart/form-data") in the POST function, and something like pdf = upload_file("~/Desktop/myPDF.pdf") inside the the_body list. But haven't succeeded

UPDATE: I got to send an attachment file with what I commented above. But can't send more than one in the same email! Is it possible? tried a list for attachment inside the the_body but doesn't work.

Pimped it up a little: https://github.com/laresbernardo/lares/blob/master/R/mails.R
Just need to know how to send multiple attachments for it to fully work!

Sorry I missed your comment @laresbernardo, they only just started sending notifications.