ResponseParseError in `envelope`: unknown token - #{???}

Parse errors in envelope fields. I'll add more details about these later. Right now I only have the stacktraces and the error message. These might be bugs in our code, or they might be server errors that we need to handle more gracefully.

Net::IMAP::ResponseParseError: unknown token - ""Fwd:"

/bundler/gems/net-imap-e76475223002/lib/net/imap/response_parser/parser_utils.rb:224 in parse_error
/bundler/gems/net-imap-e76475223002/lib/net/imap/response_parser.rb:1620 in next_token
/bundler/gems/net-imap-e76475223002/lib/net/imap/response_parser/parser_utils.rb:96 in NIL?
/bundler/gems/net-imap-e76475223002/lib/net/imap/response_parser.rb:362 in nstring
/bundler/gems/net-imap-e76475223002/lib/net/imap/response_parser.rb:542 in envelope
/bundler/gems/net-imap-e76475223002/lib/net/imap/response_parser.rb:529 in envelope_data
/bundler/gems/net-imap-e76475223002/lib/net/imap/response_parser.rb:502 in msg_att
/bundler/gems/net-imap-e76475223002/lib/net/imap/response_parser.rb:482 in numeric_response
/bundler/gems/net-imap-e76475223002/lib/net/imap/response_parser.rb:416 in response_untagged
/bundler/gems/net-imap-e76475223002/lib/net/imap/response_parser.rb:387 in response
/bundler/gems/net-imap-e76475223002/lib/net/imap/response_parser.rb:33 in parse

Net::IMAP::ResponseParseError: unknown token - "=E2=80=9DStar_Action_Shots""

/bundler/gems/net-imap-e76475223002/lib/net/imap/response_parser/parser_utils.rb:224 in parse_error
/bundler/gems/net-imap-e76475223002/lib/net/imap/response_parser.rb:1620 in next_token
/bundler/gems/net-imap-e76475223002/lib/net/imap/response_parser/parser_utils.rb:170 in lookahead
/bundler/gems/net-imap-e76475223002/lib/net/imap/response_parser/parser_utils.rb:134 in match
/bundler/gems/net-imap-e76475223002/lib/net/imap/response_parser.rb:1468 in address
/bundler/gems/net-imap-e76475223002/lib/net/imap/response_parser.rb:1437 in address_list
/bundler/gems/net-imap-e76475223002/lib/net/imap/response_parser.rb:550 in envelope
/bundler/gems/net-imap-e76475223002/lib/net/imap/response_parser.rb:529 in envelope_data
/bundler/gems/net-imap-e76475223002/lib/net/imap/response_parser.rb:502 in msg_att
/bundler/gems/net-imap-e76475223002/lib/net/imap/response_parser.rb:482 in numeric_response
/bundler/gems/net-imap-e76475223002/lib/net/imap/response_parser.rb:416 in response_untagged
/bundler/gems/net-imap-e76475223002/lib/net/imap/response_parser.rb:387 in response
/bundler/gems/net-imap-e76475223002/lib/net/imap/response_parser.rb:33 in parse

Net::IMAP::ResponseParseError: unexpected token NUMBER (expected SPACE)

/bundler/gems/net-imap-e76475223002/lib/net/imap/response_parser.rb:557 in envelope
/bundler/gems/net-imap-e76475223002/lib/net/imap/response_parser.rb:529 in envelope_data
/bundler/gems/net-imap-e76475223002/lib/net/imap/response_parser.rb:502 in msg_att
/bundler/gems/net-imap-e76475223002/lib/net/imap/response_parser.rb:482 in numeric_response
/bundler/gems/net-imap-e76475223002/lib/net/imap/response_parser.rb:416 in response_untagged
/bundler/gems/net-imap-e76475223002/lib/net/imap/response_parser.rb:387 in response

Start by reviewing the envelope parsing paths in response_parser.rb, especially envelope, envelope_data, address_list, and nstring, alongside the parser_utils.rb locations shown in the stack traces. Reproduce the reported inputs if they can be obtained, then define expected handling for each parse error and add regression coverage before considering the issue complete.