iOS Mail app generates invalid headers

iOS Mail app generates e-mail headers such as this:

Cc: "Pop =?UTF-8?B?Wm9sdMOhbiI=?=  <user@tld.com>

RFC822 specifies how strings can be quoted with

<">         =  <ASCII quote mark>
quoted-string = <"> *(qtext/quoted-pair) <">

RFC1342 specifies how non-ASCII text can be encoded

encoded-word = "=" "?" charset "?" encoding "?" encoded-text "?" "="
encoded-text = 1*<Any printable ASCII character other than "?" or
                  ; SPACE> (but see "Use of encoded-words in message
                  ; headers", below)

Although not explicitely prohibited by RFC1342, encoding the enclosing quote while not encoding the starting quote causes server-side SMTP processing to fail, if decoding is not performed before quote processing. IMO, quotes should NOT be encoded as per the intent of RFC822 to use the ASCII quote mark as delimiter.