sasl connection refused
reddit / selfhosted

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kajvans · 2023-12-14 12:54

Hi everyone,

i am trying to host my own mail server using postfix and dovecot. I
started first with only postfix and that worked but i wanted to use a
mailclient so i installed thunderbird but now i get the error when
receiving and sending mail:


    Dec 14 12:50:56 debian postfix/smtpd[33959]: warning: SASL:
Connect to private/auth failed: Connection refused
    Dec 14 12:50:56 debian postfix/smtpd[33959]: fatal: no SASL
authentication mechanisms
    Dec 14 12:50:57 debian postfix/master[27335]: warning: process
/usr/lib/postfix/sbin/smtpd pid 33959 exit status 1
    Dec 14 12:50:57 debian postfix/master[27335]: warning:
/usr/lib/postfix/sbin/smtpd: bad command startup -- throttling

i sadly dont know how to fix this and tried searching it but dont see
anything really useful. If someone could help it would be really
appreciated.
thanks in advance

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KD_done · 2023-12-14 14:14

yeah.. so, tell dovecot what backend to use, otherwise the dovecot lda
(the tool that helps perform the sasl auth) doesn't know what to do
(or say).

So, in your dovecot-master.cf , look for   " service auth {  " .. and
depending on the backend you use you can fix it there.

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kajvans · 2023-12-14 15:01

i think i found the problem, dovecot does not create the
/var/spool/postfix/private/auth file but whatever i do it is not
creating it

dovecot -n output:

    auth_mechanisms = plain login
    auth_mechanisms = plain login
mail_location = maildir:~/Maildir
mail_privileged_group = mail
namespace inbox {
  inbox = yes
  location =
  mailbox Drafts {
    special_use = \Drafts
  }
  mailbox Junk {
    special_use = \Junk
  }
  mailbox Sent {
    special_use = \Sent
  }
  mailbox "Sent Messages" {
    special_use = \Sent
  }
  mailbox Trash {
    special_use = \Trash
  }
  prefix =
}
passdb {
  driver = pam
}
protocols = " imap"
service auth {
  unix_listener /var/spool/postfix/private/auth {
    group = postfix
    mode = 0660
    user = postfix
  }
}
ssl_cert = </etc/dovecot/private/dovecot.pem
ssl_client_ca_dir = /etc/ssl/certs
ssl_dh = # hidden, use -P to show it
ssl_key = # hidden, use -P to show it
userdb {
  driver = passwd
}

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KD_done · 2023-12-14 15:56

Okay.. well, it might be the case that the user postfix is not allowed
to create a file there.. so, with touch, create an empty file with the
correct filename..

afterwards: chown postfix:postfix $filename

Remember, if you change the user & group in the auth config, change
the ownership of the file!

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kajvans · 2023-12-15 12:50

i think it fixed it. with telnet i finally get an output with ehlo
localhost so thanks

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KD_done · 2023-12-15 20:41

Excellent news! Nice one :)

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kajvans · 2023-12-15 21:01

oke now connecting and receiving with dovecot works only i cant
connect to port 25, so i cant sent any mail. this also is the case
when using telnet on another machine. but when i use telnet on the
local device using the [mail.domayn.com](https://mail.domayn.com) url
it works fine but not on other machines. maybe any ideas?

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KD_done · 2023-12-15 21:24

Well.. you know your layout/network better than anyone else, so I'm
not going to start a guessing game trying to find out how your network
is actually setup :)

But.. with telnet, nmap and turning on/off firewalls, you can
eliminate infrastructure.

But start with "lsof -i 4|grep smtp"  on the box that has the
mailserver.. and work your way out.

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kajvans · 2023-12-15 21:57

oké i use ufw and port is open and i can ping the port without any
problems. but the moment when i try to use telnet or connect to the
port. also with disabled firewall i cant connect. i tried disabling
all helo lines in postfix but it did not fix anything and since i can
ping the port it is accessible. so i dont think it is network related
but postfix related.

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KD_done · 2023-12-15 23:45

I don't understand what you mean by "ping the port" ..

And with smtp listening on everyting, does this works?

    mark@mail:~$ telnet localhost 25
Trying 127.0.0.1...
Connected to localhost.
Escape character is '^]'.
220 mail.oznb.net ESMTP Postfix curd
QUIT
221 2.0.0 Bye
Connection closed by foreign host.Connection closed by foreign host.

And, then from a different node on.. and see if that works? I'm having
a hard time following what you are testing (and how).