Maybe this is the issue? I am seeing TLSv1? I think Microsoft deprecated that. I have tried to update the config file but cannot get it to show anything but v1.
Global options:
debug = daemon.notice
pid = /var/run/stunnel.pid
RNDbytes = 64
RNDfile = /dev/urandom
RNDoverwrite = yes
Service-level options:
ciphers = FIPS (with "fips = yes")
ciphers = ALL:!SSLv2:!aNULL:!EXP:!LOW:-MEDIUM:RC4:+HIGH (with "fips = no")
curve = prime256v1
sessionCacheSize = 1000
sessionCacheTimeout = 300 seconds
sslVersion = TLSv1 (with "fips = yes")
sslVersion = TLSv1 for client, all for server (with "fips = no")
stack = 65536 bytes
TIMEOUTbusy = 300 seconds
TIMEOUTclose = 60 seconds
TIMEOUTconnect = 10 seconds
TIMEOUTidle = 43200 seconds
verify = none
From: Ben Bazian via stunnel-users <stunnel-users@stunnel.org>
Sent: Tuesday, October 26, 2021 10:55 AM
To: jose isaias cabrera <jicman@gmail.com>; stunnel-users@stunnel.org
Subject: [stunnel-users] Office 365 connections stopped working
[E X T E R N A L]
This has been working for years and recently stopped. I am a novice here. Can someone look at this and please tell me what is happening? It is an old server that does not support TLS so we put Stunnel in front of it. I am sure the version
of stunnel is pretty old. Maybe a TLS level issue?
2021.10.26 14:47:30 LOG7[21968:139797665822784]: SSL options set: 0x01000004
2021.10.26 14:47:30 LOG6[21968:139797665822784]: Initializing service [SMTP Outgoing]
2021.10.26 14:47:30 LOG7[21968:139797665822784]: SSL options set: 0x01000004
2021.10.26 14:47:30 LOG6[21968:139797665822784]: Initializing service [IMAP]
2021.10.26 14:47:30 LOG7[21968:139797665822784]: SSL options set: 0x01000004
2021.10.26 14:47:30 LOG5[21968:139797665822784]: Configuration successful
2021.10.26 14:47:30 LOG7[21968:139797665822784]: Service [POP3 Incoming] (FD=12) bound to 0.0.0.0:110
2021.10.26 14:47:30 LOG7[21968:139797665822784]: Service [SMTP Outgoing] (FD=13) bound to 0.0.0.0:25
2021.10.26 14:47:30 LOG7[21968:139797665822784]: Service [IMAP] (FD=14) bound to 0.0.0.0:143
2021.10.26 14:47:30 LOG7[21974:139797665822784]: Created pid file /var/run/stunnel.pid
2021.10.26 14:48:30 LOG7[21974:139797665822784]: Service [IMAP] accepted (FD=3) from 10.55.3.159:1852
2021.10.26 14:48:30 LOG7[21974:139797665818368]: Service [IMAP] started
2021.10.26 14:48:30 LOG7[21974:139797665818368]: Waiting for a libwrap process
2021.10.26 14:48:30 LOG7[21974:139797665818368]: Acquired libwrap process #0
2021.10.26 14:48:30 LOG7[21974:139797665818368]: Releasing libwrap process #0
2021.10.26 14:48:30 LOG7[21974:139797665818368]: Released libwrap process #0
2021.10.26 14:48:30 LOG7[21974:139797665818368]: Service [IMAP] permitted by libwrap from 10.55.3.159:1852
2021.10.26 14:48:30 LOG5[21974:139797665818368]: Service [IMAP] accepted connection from 10.55.3.159:1852
2021.10.26 14:48:30 LOG6[21974:139797665818368]: connect_blocking: connecting 52.96.87.226:993
2021.10.26 14:48:30 LOG7[21974:139797665818368]: connect_blocking: s_poll_wait 52.96.87.226:993: waiting 10 seconds
2021.10.26 14:48:30 LOG5[21974:139797665818368]: connect_blocking: connected 52.96.87.226:993
2021.10.26 14:48:30 LOG5[21974:139797665818368]: Service [IMAP] connected remote server from 10.55.3.200:51358
2021.10.26 14:48:30 LOG7[21974:139797665818368]: Remote socket (FD=16) initialized
2021.10.26 14:48:30 LOG7[21974:139797665818368]: SNI: sending servername: outlook.office365.com
2021.10.26 14:48:30 LOG7[21974:139797665818368]: SSL state (connect): before/connect initialization
2021.10.26 14:48:30 LOG7[21974:139797665818368]: SSL state (connect): SSLv3 write client hello A
2021.10.26 14:48:30 LOG3[21974:139797665818368]: SSL_connect: Peer suddenly disconnected
2021.10.26 14:48:30 LOG5[21974:139797665818368]: Connection reset: 0 byte(s) sent to SSL, 0 byte(s) sent to socket
2021.10.26 14:48:30 LOG7[21974:139797665818368]: Remote socket (FD=16) closed
2021.10.26 14:48:30 LOG7[21974:139797665818368]: Local socket (FD=3) closed
2021.10.26 14:48:30 LOG7[21974:139797665818368]: Service [IMAP] finished (0 left)