[stunnel-users] Stunnel never really connects

Pat Riehecky prieheck at iwu.edu
Wed Dec 19 16:31:53 CET 2007

I am trying to send email over stunnel from a client that doesn't
support encryption to a server that does.

The local socket opens just fine, but it never really seems to connect
to the remote server.  A tcpdump shows only three packets exchanged
between the two systems (Syn, Syn/Ack, Ack).  The behavior is the same
regardless of which tls enabled port I point stunnel at.  I am able to
connect to these ports via telnet and send email so I know the
connection can be negotiated.

I am using the 4.21 build for windows (XP SP2) found on the main


--- stunnel.conf ---

; Some performance tunings
socket = l:TCP_NODELAY=1
socket = r:TCP_NODELAY=1

; Workaround for Eudora bug
; my email client isn't eudora, but given how
; it doesn't support standards like encrypted
; transport..... 

; Some debugging stuff useful for troubleshooting
debug = 7

; Use it for client mode
client = yes

accept  =
connect = mailserver.mydomain.tld:587
;connect = mailserver.mydomain.tld:465
;connect = mailserver.mydomain.tld:25
protocol = smtp
-------------- next part --------------
A non-text attachment was scrubbed...
Name: stunnel_log.png
Type: image/png
Size: 18571 bytes
Desc: not available
URL: <http://www.stunnel.org/pipermail/stunnel-users/attachments/20071219/2605a7ef/attachment.png>

More information about the stunnel-users mailing list