i used a little tool to talk to your server and it is responding on port 25 so SMTP is talking outside of your network.
Connecting to mail server.
Connected.
220 amanet.site ESMTP Postfix (Ubuntu)
EHLO e6540
250-amanet.site
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
250 CHUNKING
RSET
250 2.0.0 Ok
MAIL FROM: <test@example.com>
250 2.1.0 Ok
RCPT TO: <test@example.com>
454 4.7.1 <test@example.com>: Relay access denied
Error: SMTP protocol error. 454 4.7.1 <test@example.com>: Relay access denied.
Failed to send messageForcing disconnection from SMTP server.
QUIT
221 2.0.0 Bye
Disconnected.
- Login with usermin and see what its webmail shows you… I think usermin connects directly to the mail store whereas Roundcube uses the IMAP protocol.
- You are not on any blacklists, but your DNS is not propagated
- DNS Checker - DNS Check Propagation Tool
- your rDNS for 207.148.23.231 resolves to 207.148.23.231.vultrusercontent.com. = maybe the other email servers are just flat out blocking you because of this.
- Do you need to get vultru… to enable sending emails
- vultr server cant send emails to domain
Vultr block port 25 because it’s often abused. Raise a ticket for them to open it.
What Ports Are Blocked? - Vultr.com