I have modified c-client to set "Return-Receipt-To" when needed.
For what it's worth, that is a completely deprecated feature of sendmail and should not be used by modern software.
But on the other hand I would rather use an unmodified c-client library - any thoughts on these header values in future imap versions?
Presumably your modifications are to rfc822_header(). You almost never want to use that function in a sophisticated program due to the lack of buffer overflow checking. Instead, you want to define an rfc822out_t function that you arm via mail_parameters() with SET_RFC822OUTPUT, and that function does the following:
if (ok8bit) rfc822_encode_body_8bit (env,body);
else rfc822_encode_body_7bit (env,body);
/* write code to do the work ofrfc822_header() here, leaving
pointer to header in t */
return (*f) (s,t) && (body ? rfc822_output_body (body,f,s) : T);
By doing this, you have no need to modify c-client.
-- Mark --
http://staff.washington.edu/mrc Science does not emerge from voting, party politics, or public debate. Si vis pacem, para bellum.
