class Net::IMAP::FetchData
See FetchStruct documentation for a list of standard message attributes.
the UIDONLY
extension is enabled.
Net::IMAP#uid_store all return arrays of FetchData objects, except when
Net::IMAP#fetch, Net::IMAP#uid_fetch, Net::IMAP#store, and
Net::IMAP::FetchData represents the contents of a FETCH
response.