[stunnel-users] Stunnel not working with Office 365

[Hannu Viitala]

Hi,

We cannot get stunnel SMTP to work with Office 365 mail server. We are using Stunnel  5.13 and below are the config file content and the the client PC logs. The mail server logs do not reveal anything more.

Two observations of the test setup:


1)      Using e.g. Mozilla Firebird mail client directly SLL/SMTP on the same PC connection to same Office 365 mail server works ok, but via Stunnel it outputs the error log below.

2)      Also, on the same PC, SSL/SMTP connection via stunnel to Gmail server works ok.

Stunnel conf-file:
==============

output = stunnel_log.txt
debug = debug
cert = tstunnel.pem
client = yes

[SSMTP]
accept =  127.0.0.1:54500
connect = xxx.xxx.xxx.xxx:587 (Hannu V: removed IP address from this mail)
protocol = smtp



Client PC logs:
===========

2015.04.28 09:17:36 LOG7[ui]: No limit detected for the number of clients
2015.04.28 09:17:36 LOG5[ui]: stunnel 5.13 on x86-pc-msvc-1500 platform
2015.04.28 09:17:36 LOG5[ui]: Compiled/running with OpenSSL 1.0.2a 19 Mar 2015
2015.04.28 09:17:36 LOG5[ui]: Threading:WIN32 Sockets:SELECT,IPv6 TLS:ENGINE,FIPS,OCSP,PSK,SNI
2015.04.28 09:17:36 LOG7[ui]: errno: (*_errno())
2015.04.28 09:17:36 LOG5[ui]: Reading configuration from file tstunnelSmtp_SAUX1_0.conf
2015.04.28 09:17:36 LOG5[ui]: UTF-8 byte order mark not detected
2015.04.28 09:17:36 LOG5[ui]: FIPS mode disabled
2015.04.28 09:17:36 LOG7[ui]: Compression disabled
2015.04.28 09:17:36 LOG7[ui]: PRNG seeded successfully
2015.04.28 09:17:36 LOG6[ui]: Initializing service [SSmtp]
2015.04.28 09:17:36 LOG6[ui]: Loading certificate from file: tstunnel.pem
2015.04.28 09:17:36 LOG6[ui]: Loading key from file: tstunnel.pem
2015.04.28 09:17:36 LOG7[ui]: Private key check succeeded
2015.04.28 09:17:36 LOG7[ui]: SSL options: 0x03000004 (+0x03000000, -0x00000000)
2015.04.28 09:17:36 LOG5[ui]: Configuration successful
2015.04.28 09:17:36 LOG7[ui]: Listening file descriptor created (FD=448)
2015.04.28 09:17:36 LOG7[ui]: Service [SSmtp] (FD=448) bound to 127.0.0.1:8030
2015.04.28 09:17:36 LOG7[ui]: Service [SSmtp] accepted (FD=456) from 127.0.0.1:54500
2015.04.28 09:17:36 LOG7[ui]: Creating a new thread
2015.04.28 09:17:36 LOG7[ui]: New thread created
2015.04.28 09:17:36 LOG7[0]: Service [SSmtp] started
2015.04.28 09:17:36 LOG5[0]: Service [SSmtp] accepted connection from 127.0.0.1:54500
2015.04.28 09:17:36 LOG6[0]: s_connect: connecting xxx.xxx.xxx.xxx:587    (Hannu V: removed IP address from this mail)
2015.04.28 09:17:36 LOG7[0]: s_connect: s_poll_wait connecting xxx.xxx.xxx.xxx:587    : waiting 10 seconds (Hannu V: removed IP address from this mail)
2015.04.28 09:17:37 LOG5[0]: s_connect: connected connecting xxx.xxx.xxx.xxx:587    (Hannu V: removed IP address from this mail)
2015.04.28 09:17:37 LOG5[0]: Service [SSmtp] connected remote server from yyy.yyy.yyy.yyy:54503 (Hannu V: removed IP address from this mail)
2015.04.28 09:17:37 LOG7[0]: Remote socket (FD=472) initialized
2015.04.28 09:17:37 LOG7[0]:  <- 220 NNN.outlook.office365.com Microsoft ESMTP MAIL Service ready at Tue, 28 Apr 2015 14:17:38 +0000
2015.04.28 09:17:37 LOG7[0]:  -> 220 NNN.outlook.office365.com Microsoft ESMTP MAIL Service ready at Tue, 28 Apr 2015 14:17:38 +0000
2015.04.28 09:17:37 LOG7[0]:  -> EHLO localhost
2015.04.28 09:17:37 LOG7[0]:  <- 250-NNN.outlook.office365.com Hello [xxx.xxx.xxx.161] (Hannu V: removed IP address from this mail)
2015.04.28 09:17:37 LOG7[0]:  <- 250-SIZE 157286400
2015.04.28 09:17:37 LOG7[0]:  <- 250-PIPELINING
2015.04.28 09:17:37 LOG7[0]:  <- 250-DSN
2015.04.28 09:17:37 LOG7[0]:  <- 250-ENHANCEDSTATUSCODES
2015.04.28 09:17:37 LOG7[0]:  <- 250-STARTTLS
2015.04.28 09:17:37 LOG7[0]:  <- 250-8BITMIME
2015.04.28 09:17:37 LOG7[0]:  <- 250-BINARYMIME
2015.04.28 09:17:37 LOG7[0]:  <- 250 CHUNKING
2015.04.28 09:17:37 LOG7[0]:  -> STARTTLS
2015.04.28 09:17:37 LOG7[0]:  <- 220 2.0.0 SMTP server ready
2015.04.28 09:17:37 LOG6[0]: SNI: sending servername: NNN.office365.com
2015.04.28 09:17:37 LOG7[0]: SSL state (connect): before/connect initialization
2015.04.28 09:17:37 LOG7[0]: SSL state (connect): SSLv2/v3 write client hello A
2015.04.28 09:17:37 LOG7[0]: SSL state (connect): SSLv3 read server hello A
2015.04.28 09:17:37 LOG7[0]: SSL state (connect): SSLv3 read server certificate A
2015.04.28 09:17:37 LOG7[0]: SSL state (connect): SSLv3 read server key exchange A
2015.04.28 09:17:37 LOG7[0]: SSL state (connect): SSLv3 read server certificate request A
2015.04.28 09:17:37 LOG7[0]: SSL state (connect): SSLv3 read server done A
2015.04.28 09:17:37 LOG7[0]: SSL state (connect): SSLv3 write client certificate A
2015.04.28 09:17:37 LOG7[0]: SSL state (connect): SSLv3 write client key exchange A
2015.04.28 09:17:37 LOG7[0]: SSL state (connect): SSLv3 write certificate verify A
2015.04.28 09:17:37 LOG7[0]: SSL state (connect): SSLv3 write change cipher spec A
2015.04.28 09:17:37 LOG7[0]: SSL state (connect): SSLv3 write finished A
2015.04.28 09:17:37 LOG7[0]: SSL state (connect): SSLv3 flush data
2015.04.28 09:17:37 LOG3[0]: SSL_connect: Peer suddenly disconnected
2015.04.28 09:17:37 LOG5[0]: Connection reset: 0 byte(s) sent to SSL, 0 byte(s) sent to socket
2015.04.28 09:17:37 LOG7[0]: Remote socket (FD=472) closed
2015.04.28 09:17:37 LOG7[0]: Local socket (FD=456) closed
2015.04.28 09:17:37 LOG7[0]: Service [SSmtp] finished (0 left)




--- Hannu

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