Re: [Imap-protocol] Working around the evils of LITERAL+

Takeshi Chiba <[email protected]>
Newsgroups gmane.mail.imap.general
Message-ID <[email protected]>
It seems like not general problem but gmail :-)
(There are many special clients for gmail such as gmail filesystem)

If I were gmail developper, eat the data *slowly*.

  C: tag APPEND INBOX {1000000+}
  S: tag NO quota limit exceeded
  C: From: [email protected]
  S: From: BAD unknown command
  C: To: [email protected]
  S: To: BAD unknown command
  C: Subject: i-node
  (server detect bad client by several invalid command, so sleep 10 seconds)
  S: Subject: BAD unknown command
  C: Date: ...
  (sleep 10 seconds)
  S: Date: BAD unknown command
  ...

-- 
Takeshi Chiba

(2013/03/27 6:26), Brandon Long wrote:
> More than a year ago, we (Gmail) disabled LITERAL+ on our servers.
>
> This was because of some unfortunate combination of factors.  For one, we have a maximum message size on our server, with no real way to make that available to
> IMAP (maybe via GETQUOTA, but if no clients check it, that's not that useful).  For two, we have an inbound bandwidth quota to protect against both broken
> clients and attempts to use Gmail IMAP as a storage system.
>
> So, if a user attempted to draft a message larger than our limit (35MB), with LITERAL+, the client would just issue an APPEND with two large a message.  Our
> options were to just eat the data and say NO afterwards (great waste of bandwidth) or drop the connection.  Some clients would just keep retrying to do the
> APPEND until they exhausted the upload bandwidth quota, or just cost the user a lot of money if they happened to be on a line that charged.
>
> So, we disabled LITERAL+... but now I watch some UTF-8 SEARCH commands that have N literals in them, each requiring a server response, its just kind of evil.
>
> I guess we could have the server learn that a user is using a bad client and disable LITERAL+ automatically, anyone have any other ideas?
>
> Brandon
>
>
> _______________________________________________
> Imap-protocol mailing list
> [email protected]
> http://mailman2.u.washington.edu/mailman/listinfo/imap-protocol
>

_______________________________________________
Imap-protocol mailing list
[email protected]
http://mailman2.u.washington.edu/mailman/listinfo/imap-protocol
lmpx.com only provides a reader for public news (NNTP) servers. It is not affiliated with the servers or forums shown here and is not responsible for the content of articles, which is written by their respective authors.