HI all guys, i configured my server a month ago but im havin problems with spam, i just followed all the steps in perfect setup ubuntu 5.10, but anyone can send emails throught smtp without authentification. For example i telnet to my server to port 25(i tried from an outside ip and it worked). So when i look to my mail logs, im noticing that some people is using my server to send emails.... anyone could help me? thks in advanced
First, did you try to send emails to a domain on your server or to an external domain. Your server is only an open relay if someone can send email to e.g. a gmail account without authentication. Please post your postfix main.cf file here.
this is my output to ehlo , i think its right because is starttls and AUTH... 501 Syntax: EHLO hostname ehlo server.com 250-server1.mydomain.com 250-PIPELINING 250-SIZE 10240000 250-VRFY 250-ETRN 250-STARTTLS 250-AUTH LOGIN PLAIN 250-AUTH=LOGIN PLAIN 250 8BITMIME this is my main.cf from /etc/postfix # See /usr/share/postfix/main.cf.dist for a commented, more complete version smtpd_banner = $myhostname ESMTP $mail_name biff = no # appending .domain is the MUA's job. append_dot_mydomain = no # Uncomment the next line to generate "delayed mail" warnings #delay_warning_time = 4h myhostname = server1.mydomain.com alias_maps = hash:/etc/aliases alias_database = hash:/etc/aliases myorigin = /etc/mailname #mydestination = server1.mydomain.com, localhost.mydomain.com, localhost relayhost = mynetworks = 127.0.0.0/8 mailbox_size_limit = 0 recipient_delimiter = + inet_interfaces = all mailbox_command = smtpd_sasl_local_domain = smtpd_sasl_auth_enable = yes smtpd_sasl_security_options = noanonymous broken_sasl_auth_clients = yes smtpd_recipient_restrictions = permit_sasl_authenticated,permit_mynetworks,reject_unauth_destination smtpd_tls_auth_only = no smtp_use_tls = yes smtpd_use_tls = yes smtp_tls_note_starttls_offer = yes smtpd_tls_key_file = /etc/postfix/ssl/smtpd.key smtpd_tls_cert_file = /etc/postfix/ssl/smtpd.crt smtpd_tls_CAfile = /etc/postfix/ssl/cacert.pem smtpd_tls_loglevel = 1 smtpd_tls_received_header = yes smtpd_tls_session_cache_timeout = 3600s tls_random_source = dev:/dev/urandom home_mailbox = Maildir/ virtual_maps = hash:/etc/postfix/virtusertable mydestination = /etc/postfix/local-host-names
There are three scenarios when you don't have to authenticate when you want to send mails: You're sending directly from the server, e.g. with webmail. You're sending to e recipient whose mailbox is on the server. You're sending from a computer that is within mynetworks in /etc/postfix7main.cf.
ok, falko i understand but my networks only responds to 127.0.0.0/8 so if i tried from a machine from my local network 192.168.1.x , i must auth because it's not on my networks and i can send mails to any external domain, like hotmail, gmail etc... thks in advanced
falko i think that the problem is solved i dont know how another question this is normal ? 220 server1.example.com ESMTP Postfix ehlo test.com 250-server1.example.com 250-PIPELINING 250-SIZE 10240000 250-VRFY 250-ETRN 250-STARTTLS 250-AUTH LOGIN PLAIN 250-AUTH=LOGIN PLAIN 250 8BITMIME mail from: [email protected] 501 Bad address syntax mail from: [email protected] 501 Syntax: MAIL FROM: <address> MAIL FROM: [email protected] 250 Ok RCPT TO: [email protected] 554 <[email protected]>: Relay access denied but when the auth is require? if i dont auth this is the message ? thks in advanced
SMTP-Auth is required everytime you send an email to a domain that is not hosted on your server and where the sending host is not in mynetworks.
