[stunnel-users] Stunnel 4.33 last one to work with VM & IMAP

Drew McDermott drew.mcdermott at yale.edu
Tue Nov 29 20:35:35 CET 2011

I am running VM 8.1, the Emacs mail reader, connecting via imap to
gmail.  It can be made to work with stunnel 4.33 providing the
encryption, but any version after that causes VM to choke when
fetching messages, generating the following error message:

vm-imap-protocol-error: IMAP protocol error: "unexpected char (10)"

Not being an expert in any of the programs that are chained together
to make my e-mail setup work, I was able to trace this no deeper than
the point where VM reads the buffer Emacs uses for interprocess
communication.  Sure enough, there is a linefeed in a place where it
isn't expected, but it also happens to be the first character in the

Process IMAP over SSL finished

which may be there because of problems deeper than the representation
of "newline."  At the end of this message I give my attempt to
represent the complete contents of the buffer with name 
"trace of IMAP over SSL session to imap.gmail.com."  The ^M's were
inserted by hand because cutting and pasting didn't seem to reproduce

I realize that I am providing quite a bit of information from VM, and
none from stunnel, which is frustrating in an stunnel forum, but I am
a complete newbie regarding stunnel.  I would be glad to run further
experiments with guidance on how to get stunnel itself to generate
more useful information. The only reason I suspect it is that
installing version 4.33 fixes the problem; but I realize it may be
that VM or some other component is violating the rules somehow.

When I say "any version after" 4.33, I mean that I have tried 4.35,
the version installed by MacPorts; and 4.49, the latest stable
version, recompiled by hand.  They behave identically.

                                             -- Drew McDermott
                                                Professor of Computer Science
                                                Yale Computer Science Department

The interprocess-communication buffer (everything between the dashes,
including the newline after "finished," but not including the newline
before "starting"):

starting IMAP over SSL session Tue Nov 29 14:20:01 2011
connecting to imap.gmail.com:993
* OK Gimap ready for requests from s17if7011003qao.19

Process IMAP over SSL finished

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