Incorrect encoding with Subject part of a mail

[grepinsight]

I am trying to send a email with Korean text in the Subject. It doesn't get encoded correctly, even thought it does in body:

Here's a minimal reproducible sample.

use_secret_file("my_gmailr.json")
mail_title <- "[test]  안녕"
test_email <- mime(
  To = "myemailgmail.com",
  From = "myemailgmail.com",
  Subject = mail_title,
  body = " 
contents. 한국어
  ")
send_message(test_email)

# In gmail
Subject: [test] 안녕      # somehow encoding/decoding get's messed up
Body: contents. 한국어  # renders it fine

Here's my sessionInfo

> sessionInfo()
R version 3.3.1 (2016-06-21)
Platform: x86_64-w64-mingw32/x64 (64-bit)
Running under: Windows >= 8 x64 (build 9200)

locale:
[1] LC_COLLATE=English_United States.1252  LC_CTYPE=English_United States.1252   
[3] LC_MONETARY=English_United States.1252 LC_NUMERIC=C                          
[5] LC_TIME=English_United States.1252    

attached base packages:
[1] stats     graphics  grDevices utils     datasets  methods   base     

other attached packages:
[1] gmailr_0.7.1

loaded via a namespace (and not attached):
 [1] httr_1.2.1      magrittr_1.5    R6_2.1.2        tools_3.3.1     base64enc_0.1-3 curl_0.9.7     
 [7] crayon_1.3.2    stringi_1.1.1   jsonlite_1.2    openssl_0.9.4  

[grepinsight]

I also tested it on my mac as well, to no avail :(

> sessionInfo()
R version 3.2.4 (2016-03-10)
Platform: x86_64-apple-darwin13.4.0 (64-bit)
Running under: OS X 10.12.2 (unknown)


locale:
[1] en_US.UTF-8/en_US.UTF-8/en_US.UTF-8/C/en_US.UTF-8/en_US.UTF-8


attached base packages:
[1] stats     graphics  grDevices utils     datasets  methods   base     


other attached packages:
[1] gmailr_0.7.1


loaded via a namespace (and not attached):
 [1] httr_1.1.0      magrittr_1.5    R6_2.1.2        tools_3.2.4     base64enc_0.1-3 curl_0.9.7     
 [7] crayon_1.3.2    Rcpp_0.12.7     jsonlite_0.9.19 httpuv_1.3.3    openssl_0.9.2  

[krlmlr]

You could use RFC 1342 (thanks to https://ncona.com/2011/06/using-utf-8-characters-on-an-e-mail-subject/):

mime(..., Subject = paste0("=?utf-8?B?", base64enc::base64encode(charToRaw(enc2utf8("안녕"))), "?=")