IMAP mailbox names are transmitted in the modified UTF-7 encoding of RFC
3501 (section 5.1.3): non-ASCII runs are written as &<base64>-,
where the base64 alphabet uses , instead of / and carries no
padding, and a literal & is written &-. mRpostman
applies the encoding to every folder name it sends and decodes the names
it receives, so folders can be referred to by their real (UTF-8) names;
these helpers are exported for users who handle raw names.
imap_utf7_encode(x)
imap_utf7_decode(x)A character vector of the same length.
imap_utf7_encode("École") # "&AMk-cole"
#> [1] "&AMk-cole"
imap_utf7_decode("&AMk-cole") # "École"
#> [1] "École"
imap_utf7_encode("Q&A") # "Q&-A"
#> [1] "Q&-A"