Does Gmail support all IMAP features?

Gmail IMAP is a fairly complete implementation of IMAP, but the following features are currently unsupported:

  • \Recent flags on messages.
  • untagged FETCH responses.
  • Substring search. All searches are assumed to be words.
  • There is no SIEVE interface to Gmail filters.
  • Only AUTH=XOAUTH and plain-text LOGIN over SSL tunneled connections are supported.
  • ENVELOPE responses for email addresses in group syntax (RFC 5322 3.4)
  • The \Answered flag is not preserved when a message is moved or a label is added to the message.