The mail server TLS port and SSL port will change

aaP_greatvpn

Sometimes the TLS port is 465 and the SSL port is 587. Sometimes the TLS port becomes 587 and the SSL port becomes 465.I have always been surprised by this problem.

aaPanel_Kern

Hello, no changes will be made by default. How did you test it?

aaP_greatvpn

aaPanel_Kern Every time I update the mail server certificate, my PHP site TLS 465 port cannot connect, but 587 can connect. Sometimes TLS 465 can connect, which is strange.

aaPanel_Kern

After updating the certificate, will trying to directly save the certificate once resolve the issue?

aaP_greatvpn

aaPanel_Kern Saving the certificate didn't solve the problem. I could only solve it by using a port. For example, the original TLS port was 465 and now I can connect using 587.

aaP_greatvpn

openssl s_client -connect mail.site.net:587 -starttls smtp Show Verify return code: 0 (ok)
openssl s_client -connect mail.site.net:465 -starttls smtp Always Show CONNECTED(00000003)

aaPanel_Kern

Hello, check if the port is in use? Are the corresponding ports open in the system firewall and server provider's security group?
netstat -tulnp|grep -E "587|465|25|110|995|143|993"

aaP_greatvpn

aaP_radipta289

aaP_greatvpn
I see now, you're testing the port with

openssl s_client -connect mail.site.net:465 -starttls smtp

Port 465 expects a direct SSL/TLS connection without the STARTTLS command, so that's why the STARTTLS handshake did not proceed as expected.

Try testing port 465 with this instead (without the -starttls smtp)

openssl s_client -connect mail.site.net:465

It looks fine to me.

Note:
Port 587 is used for SMTP submission with STARTTLS
Port 465 is used for SMTPS (SSL/TLS wrapper mode)

aaP_greatvpn

aaPanel_Kern

This seems normal. Have you tried restarting postfix? Is there a server security group? Are the relevant ports allowed?

aaP_greatvpn

aaP_radipta289

Hi @aaP_greatvpn, hope I can help you on that. Can you share your /etc/postfix/master.cf please?

aaP_greatvpn

aaP_radipta289
The problem is actually very simple, sometimes the ports of TLS and SSL are reversed, and sometimes they are normal. and the use is normal.

aaP_greatvpn

@aaP_radipta289

#
# Postfix master process configuration file.  For details on the format
# of the file, see the master(5) manual page (command: "man 5 master" or
# on-line: http://www.postfix.org/master.5.html).
#
# Do not forget to execute "postfix reload" after editing this file.
#
# ==========================================================================
# service type  private unpriv  chroot  wakeup  maxproc command + args
#               (yes)   (yes)   (no)    (never) (100)
# ==========================================================================
smtp      inet  n       -       n       -       -       smtpd
#smtp      inet  n       -       n       -       1       postscreen
#smtpd     pass  -       -       n       -       -       smtpd
#dnsblog   unix  -       -       n       -       0       dnsblog
#tlsproxy  unix  -       -       n       -       0       tlsproxy
submission inet n       -       n       -       -       smtpd
  -o syslog_name=postfix/submission
  -o smtpd_tls_security_level=encrypt
  -o smtpd_sasl_auth_enable=yes
  -o smtpd_tls_auth_only=yes
#  -o smtpd_reject_unlisted_recipient=no
#  -o smtpd_client_restrictions=$mua_client_restrictions
#  -o smtpd_helo_restrictions=$mua_helo_restrictions
#  -o smtpd_sender_restrictions=$mua_sender_restrictions
#  -o smtpd_recipient_restrictions=
  -o smtpd_relay_restrictions=permit_sasl_authenticated,reject
  -o milter_macro_daemon_name=ORIGINATING
smtps     inet  n       -       n       -       -       smtpd
  -o syslog_name=postfix/smtps
  -o smtpd_tls_wrappermode=yes
  -o smtpd_sasl_auth_enable=yes
#  -o smtpd_reject_unlisted_recipient=no
#  -o smtpd_client_restrictions=$mua_client_restrictions
#  -o smtpd_helo_restrictions=$mua_helo_restrictions
#  -o smtpd_sender_restrictions=$mua_sender_restrictions
#  -o smtpd_recipient_restrictions=
  -o smtpd_relay_restrictions=permit_sasl_authenticated,reject
  -o milter_macro_daemon_name=ORIGINATING
#628       inet  n       -       n       -       -       qmqpd
pickup    unix  n       -       n       60      1       pickup
cleanup   unix  n       -       n       -       0       cleanup
qmgr      unix  n       -       n       300     1       qmgr
#qmgr     unix  n       -       n       300     1       oqmgr
tlsmgr    unix  -       -       n       1000?   1       tlsmgr
rewrite   unix  -       -       n       -       -       trivial-rewrite
bounce    unix  -       -       n       -       0       bounce
defer     unix  -       -       n       -       0       bounce
trace     unix  -       -       n       -       0       bounce
verify    unix  -       -       n       -       1       verify
flush     unix  n       -       n       1000?   0       flush
proxymap  unix  -       -       n       -       -       proxymap
proxywrite unix -       -       n       -       1       proxymap
smtp      unix  -       -       n       -       -       smtp
relay     unix  -       -       n       -       -       smtp
        -o syslog_name=postfix/$service_name
#       -o smtp_helo_timeout=5 -o smtp_connect_timeout=5
showq     unix  n       -       n       -       -       showq
error     unix  -       -       n       -       -       error
retry     unix  -       -       n       -       -       error
discard   unix  -       -       n       -       -       discard
local     unix  -       n       n       -       -       local
virtual   unix  -       n       n       -       -       virtual
lmtp      unix  -       -       n       -       -       lmtp
anvil     unix  -       -       n       -       1       anvil
scache    unix  -       -       n       -       1       scache
#
# ====================================================================
# Interfaces to non-Postfix software. Be sure to examine the manual
# pages of the non-Postfix software to find out what options it wants.
#
# Many of the following services use the Postfix pipe(8) delivery
# agent.  See the pipe(8) man page for information about ${recipient}
# and other message envelope options.
# ====================================================================
#
# maildrop. See the Postfix MAILDROP_README file for details.
# Also specify in main.cf: maildrop_destination_recipient_limit=1
#
#maildrop  unix  -       n       n       -       -       pipe
#  flags=DRhu user=vmail argv=/usr/local/bin/maildrop -d ${recipient}
#
# ====================================================================
#
# Recent Cyrus versions can use the existing "lmtp" master.cf entry.
#
# Specify in cyrus.conf:
#   lmtp    cmd="lmtpd -a" listen="localhost:lmtp" proto=tcp4
#
# Specify in main.cf one or more of the following:
#  mailbox_transport = lmtp:inet:localhost
#  virtual_transport = lmtp:inet:localhost
#
# ====================================================================
#
# Cyrus 2.1.5 (Amos Gouaux)
# Also specify in main.cf: cyrus_destination_recipient_limit=1
#
#cyrus     unix  -       n       n       -       -       pipe
#  user=cyrus argv=/usr/lib/cyrus-imapd/deliver -e -r ${sender} -m ${extension} ${user}
#
# ====================================================================
#
# Old example of delivery via Cyrus.
#
#old-cyrus unix  -       n       n       -       -       pipe
#  flags=R user=cyrus argv=/usr/lib/cyrus-imapd/deliver -e -m ${extension} ${user}
#
# ====================================================================
#
# See the Postfix UUCP_README file for configuration details.
#
#uucp      unix  -       n       n       -       -       pipe
#  flags=Fqhu user=uucp argv=uux -r -n -z -a$sender - $nexthop!rmail ($recipient)
#
# ====================================================================
#
# Other external delivery methods.
#
#ifmail    unix  -       n       n       -       -       pipe
#  flags=F user=ftn argv=/usr/lib/ifmail/ifmail -r $nexthop ($recipient)
#
#bsmtp     unix  -       n       n       -       -       pipe
#  flags=Fq. user=bsmtp argv=/usr/local/sbin/bsmtp -f $sender $nexthop $recipient
#
#scalemail-backend unix -       n       n       -       2       pipe
#  flags=R user=scalemail argv=/usr/lib/scalemail/bin/scalemail-store
#  ${nexthop} ${user} ${extension}
#
#mailman   unix  -       n       n       -       -       pipe
#  flags=FR user=list argv=/usr/lib/mailman/bin/postfix-to-mailman.py
#  ${nexthop} ${user}

aaP_greatvpn

```openssl s_client -connect mail.picgo.net:465 -starttls smtp
CONNECTED(00000003)
Didn't find STARTTLS in server response, trying anyway...
write:errno=32
---
no peer certificate available
---
No client certificate CA names sent
---
SSL handshake has read 0 bytes and written 23 bytes
Verification: OK
---
New, (NONE), Cipher is (NONE)
Secure Renegotiation IS NOT supported
Compression: NONE
Expansion: NONE
No ALPN negotiated
Early data was not sent
Verify return code: 0 (ok)`


``openssl s_client -connect mail.picgo.net:465
CONNECTED(00000003)
depth=2 C = US, O = Internet Security Research Group, CN = ISRG Root X1
verify return:1
depth=1 C = US, O = Let's Encrypt, CN = R10
verify return:1
depth=0 CN = picgo.net
verify return:1
---
Certificate chain
 0 s:CN = picgo.net
   i:C = US, O = Let's Encrypt, CN = R10
 1 s:C = US, O = Let's Encrypt, CN = R10
   i:C = US, O = Internet Security Research Group, CN = ISRG Root X1
---
Server certificate
-----BEGIN CERTIFICATE-----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-----END CERTIFICATE-----
subject=CN = picgo.net

issuer=C = US, O = Let's Encrypt, CN = R10

---
No client certificate CA names sent
Peer signing digest: SHA256
Peer signature type: RSA-PSS
Server Temp Key: X25519, 253 bits
---
SSL handshake has read 3139 bytes and written 386 bytes
Verification: OK
---
New, TLSv1.3, Cipher is TLS_AES_256_GCM_SHA384
Server public key is 2048 bit
Secure Renegotiation IS NOT supported
Compression: NONE
Expansion: NONE
No ALPN negotiated
Early data was not sent
Verify return code: 0 (ok)
---
---
Post-Handshake New Session Ticket arrived:
SSL-Session:
    Protocol  : TLSv1.3
    Cipher    : TLS_AES_256_GCM_SHA384
    Session-ID: F6CD8EC55A283B8F078DF73F8961F0360D952D57C9D59EA938EFA04386E70533
    Session-ID-ctx: 
    Resumption PSK: F0C35F7EC2BCA8D6E428B8BDE66143553F6743E9C4C2C245C680D9BCEB178DC91165A0455A456CEDA57BB9A1407FC1FD
    PSK identity: None
    PSK identity hint: None
    SRP username: None
    TLS session ticket lifetime hint: 7200 (seconds)
    TLS session ticket:
    0000 - c2 47 17 7a da ac 54 1d-71 12 97 ee 7d a5 cb 7a   .G.z..T.q...}..z
    0010 - 76 f8 b1 d4 f6 40 51 9e-b6 e0 14 38 09 fa 09 d0   v....@Q....8....
    0020 - f1 81 d1 5b 5c bd a4 b0-34 34 33 30 56 69 70 15   ...[\...4430Vip.
    0030 - 06 13 2b 37 1b a1 0a 9a-5f 25 98 7f c1 84 09 7c   ..+7...._%.....|
    0040 - b9 5b 9c 0c 33 d0 b8 79-74 1e d1 67 63 0c 02 e8   .[..3..yt..gc...
    0050 - 9c a2 0d 74 b4 23 4d e0-7c 48 ea 91 7c 11 33 8f   ...t.#M.|H..|.3.
    0060 - 62 41 47 98 e1 98 d9 b5-5b 41 f0 14 3e 71 2e 84   bAG.....[A..>q..
    0070 - 0b f1 f5 5b e1 a4 a4 73-26 81 8f 11 90 ef fd 32   ...[...s&......2
    0080 - 57 94 f4 5c 82 c9 22 54-c4 98 ce 9c 39 10 75 5e   W..\.."T....9.u^
    0090 - da cc 49 78 9c e2 08 58-5d 4e 84 f4 97 52 74 29   ..Ix...X]N...Rt)
    00a0 - 97 aa c0 25 93 db 79 b1-fa 90 3f 61 7e ce 72 b1   ...%..y...?a~.r.
    00b0 - 5d 59 61 2b 5e db 41 ae-ba 35 eb 34 8e ca 53 be   ]Ya+^.A..5.4..S.
    00c0 - ba d4 6c 16 92 8d f1 89-52 d5 30 80 a5 5a 38 f5   ..l.....R.0..Z8.
    00d0 - 84 2b d3 5a 5c 49 e6 bb-e2 7c 4a c9 80 70 d8 3a   .+.Z\I...|J..p.:

    Start Time: 1731679393
    Timeout   : 7200 (sec)
    Verify return code: 0 (ok)
    Extended master secret: no
    Max Early Data: 0
---
read R BLOCK
220 mail.xzt.me ESMTP (Super Email)
421 4.4.2 mail.xzt.me Error: timeout exceeded