DAEMON_OPTIONS with Modifiers=A but still authentication attempts on port 25

[Jobst Schmalenbach]

Hi

I didn't know "Modifiers=A" existed until I came across this

https://www.hydrus.org.uk/journal/sendmail-noauth.html

referencing a thread in

https://groups.google.com/g/comp.mail.sendmail/c/c8x-bA07_d0

Since the discovery of "Modifiers=A" I have tried, yet the attempts are
still coming in (duplicates deleted):

Jan 9 12:28:13 mail saslauthd[1930]: : auth failure: [user=trangtry]
[service=smtp] [realm=barrett.com.au] [mech=pam] [reason=PAM auth error]
Jan 9 12:55:45 mail saslauthd[1933]: : auth failure: [user=business]
[service=smtp] [realm=barrett.com.au] [mech=pam] [reason=PAM auth error]
Jan 9 13:00:16 mail saslauthd[1929]: : auth failure:
[user=barrykennedy] [service=smtp] [realm=barrett.com.au] [mech=pam]
[reason=PAM auth error]
Jan 9 13:27:53 mail saslauthd[1930]: : auth failure: [user=psf]
[service=smtp] [realm=barrett.com.au] [mech=pam] [reason=PAM auth error]
Jan 9 13:36:06 mail saslauthd[1933]: : auth failure: [user=scr]
[service=smtp] [realm=barrett.com.au] [mech=pam] [reason=PAM auth error]


The important bits in the sendmail.mc file:

define(`confAUTH_OPTIONS', `p')
TRUST_AUTH_MECH(`EXTERNAL DIGEST-MD5 CRAM-MD5 PLAIN')
define(`confAUTH_MECHANISMS', `EXTERNAL DIGEST-MD5 CRAM-MD5 PLAIN')
DAEMON_OPTIONS(`Family=inet, Addr=101.0.102.2, Port=smtp,
Name=MTA-barrett.com.au, Modifiers=A')
DAEMON_OPTIONS(`Family=inet, Addr=127.0.0.1, Port=smtp,
Name=MTA-localhost, Modifiers=A')
DAEMON_OPTIONS(`Family=inet, Addr=101.0.102.2, Port=smtps,
Name=MTA-SSL-barrett.com.au, Modifiers=s')

versions:
cyrus-sasl.x86_64 2.1.27-6.el8_5
sendmail.x86_64 8.15.2-34.el8

[Claus Aßmann]

Post by Jobst Schmalenbach
Since the discovery of "Modifiers=A" I have tried, yet the attempts are
DAEMON_OPTIONS(`Family=inet, Addr=101.0.102.2, Port=smtp,
Name=MTA-barrett.com.au, Modifiers=A')

You can easily check it yourself:

telnet 101.0.102.2 25
wait for greeting
EHLO your.host


$ telnet 101.0.102.2 25
220 mail.barrett.com.au ESMTP SMTP
ehlo my.host
250-barrett.com.au Hello ....
250-ENHANCEDSTATUSCODES
250-PIPELINING
250-8BITMIME
250-SIZE 360000000
250-DSN
250-ETRN
250-STARTTLS
250-DELIVERBY
250 HELP
AUTH Login asb
503 5.3.3 AUTH not available

Seems to work as expected.

Hence the AUTH attempts are on a different port or from something else.

Post by Jobst Schmalenbach
sendmail.x86_64 8.15.2-34.el8

Pretty old?

[Marco Moock]

Post by Claus Aßmann

Post by Jobst Schmalenbach
sendmail.x86_64 8.15.2-34.el8

Pretty old?

The version that is being shipped with RHEL8.
el8 indicates that.

RHEL users want old versions. :-)

[Jobst Schmalenbach]

Post by Marco Moock

Post by Jobst Schmalenbach
sendmail.x86_64 8.15.2-34.el8

RHEL users want old versions. :-)

Not really ;-)

[Jobst Schmalenbach]

Post by Claus Aßmann

Post by Jobst Schmalenbach
Since the discovery of "Modifiers=A" I have tried, yet the attempts are
sendmail.x86_64 8.15.2-34.el8

Pretty old?

This is one of my bigger servers (i.e. many services) running AlmaLinux8
... difficult to "upgrade" it every time a new Alma version arrives.