I'm really stuck with a problem on my postfix installation for a few days ago. I know there is a lot of stuff about this on the net, but none of what I tried worked.
Here is my problem: I can send and receive (and read) emails to/from outside using my terminal on the server, thought SSH. I mean, when logged in my server. But I can't send email with a SMTP client through my server (outside my server network).
My server is Debian 9. I enabled SASL authentication with Cyrus SASL following the Debian wiki: https://wiki.debian.org/PostfixAndSASL#Implementation_using_Cyrus_SASL.
When I do
telnet mail.myserver.com 25 and run EHLO I get:
250-mail.myserver.com 250-PIPELINING 250-SIZE 10240000 250-VRFY 250-ETRN 250-STARTTLS 250-AUTH PLAIN LOGIN 250-AUTH=PLAIN LOGIN 250-ENHANCEDSTATUSCODES 250-8BITMIME 250-DSN 250 SMTPUTF8
I can also authenticate with base64 from telnet:
AUTH PLAIN <base64_string> 235 2.7.0 Authentication successful
/etc/postfix/main.cf I have:
smtpd_sasl_auth_enable = yes broken_sasl_auth_clients = yes smtp_tls_CAfile = /etc/ssl/certs/ca-certificates.crt smtpd_sasl_security_options = noanonymous smtpd_sasl_local_domain = $myhostname smtpd_recipient_restrictions = permit_sasl_authenticated permit_mynetworks
And the problem is as follow:
I connected my server email address (email@example.com) to my personal Gmail address thought Settings > Accounts and import > "Send mail as" on my Gmail web client. I set my smtp server, user and user password. I used port 587 and TLS. It authenticated successfully and I completed the verification process.
However, when I use Gmail to send a email with "Send as firstname.lastname@example.org", it bounces on my server. From
/var/log/mail.log I can read:
postfix/smtpd: connect from mail-ed1-f47.google.com[22.214.171.124] postfix/smtpd: Anonymous TLS connection established from mail-ed1-f47.google.com[126.96.36.199]: TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits) postfix/smtpd: NOQUEUE: reject: RCPT from mail-ed1-f47.google.com[188.8.131.52]: 554 5.7.1 <email@example.com>: Relay access denied; from=<firstname.lastname@example.org> to=<email@example.com> proto=ESMTP helo=<mail-ed1-f47.google.com> postfix/smtpd: disconnect from mail-ed1-f47.google.com[184.108.40.206] ehlo=2 starttls=1 auth=1 mail=1 rcpt=0/1 data=0/1 quit=1 commands=6/8
As I said, sending a email to firstname.lastname@example.org from my server terminal just works fine, with SPF, DKIM and DMARC pass.
I don't know what to do. I really appreciate if someone can help me with this.