[Twisted-Python] IMAP4 Proxy to add headers and modify body of an incoming message

[exarkun at twistedmatrix.com]

>From: Krzysztof Oblucki <koblucki at yahoo.com>
>To: "twisted-python at twistedmatrix.com" <twisted- 
>python at twistedmatrix.com>
>Sent: Monday, November 25, 2013 11:27 AM
>Subject: IMAP4 Proxy to add headers and modify body of an incoming 
>message
>
>Hello,
>I am trying to write an IMAP proxy to modify headers and the body of an 
>incoming message using twisted.  I am new to python and twisted so 
>maybe this is why I either picked the wrong route or don't have the 
>skills to get through some issues and I'm hoping that some you fine 
>list members can point me in the right direction.
>
>I started by using the IMAP4Client and IMAP4Server to do the proxying. 
>However, I realized that in certain cases, the IMAP4Server requires 
>synchronous results but since I need to do an async call using the 
>client the handling is not working properly.  I ran into this when 
>implementing getFlags() in the IMessage and I am not sure how I can get 
>out of this short of changing the IMAP4Server code to handle Deferreds.
>
>Am I on the right track?  Is imap4 lib the right tool for this job?  If 
>so, is modifying IMAP4Server to handle Deferreds the right thing to do? 
>If not, what would you recommend?

Sounds like you diagnosed the problem correctly.  IMAP4Server needs to 
handle Deferreds here and doesn't currently.

Jean-Paul