Problem with outgoing mail

Hi,

CentOS 6.9 with Directadmin 1.44

I have a problem with outgoing e-mail.
There is no limit on outgoing mails.
When I send an e-mail in Roundcube I get the following message back:

A message that you sent could not be delivered to one or more of its
recipients. This is a permanent error. The following address(es) failed:

**@msn.com
host smtp.mail.gtm.iss.as9143.net [212.54.42.9]
SMTP error from remote mail server after RCPT TO:<**@msn.com>:
550 Beveiligings alarm! account is geblokkeerd voor uitgaande e-mail (alarm! account is blocked for outgoing e-mail)
Reporting-MTA: dns; server01.**.nl

Action: failed
Final-Recipient: rfc822;**@msn.com
Status: 5.0.0
Remote-MTA: dns; smtp.mail.gtm.iss.as9143.net
Diagnostic-Code: smtp; 550 Beveiligings alarm! account is geblokkeerd voor uitgaande e-mail (alarm! account is blocked for outgoing e-mail)

Does anyone know what this problem can be?
There is no firewall and it always worked well. It's for my own website.

Some time ago, a lot of spam was sent from my Directadmin. I have managed to solve this. The problem was a PHP Mailer (script).

Kind regards,
Nick.

It looks like your mail server's IP address is blacklisted by the remote server, use this link and check your mail server IP address against over 100 DNS based email blacklists.

Hello Nick,

It looks as if your server provider or ISP is blocking connections from your network or server to remote 25 ports.

The IP 212.54.42.9 belongs to ZIGGO network. So I'd rather start investigating from contacting support department of ZIGGO.

I'm having Ziggo to. Are you sure you did not change anything? If you're sending via your directadmin server or account, then do not use the new Ziggo ports 465 or 587 which require authentication.
Just use port 25 without authentication. However, best is to use your own DA servers domain smtp via port 587 if you have Ziggo. Or 465 if you have SSL
Ziggo is has been changing things so I'm not amazed about this.

To my experience once a while this still can go wrong and the Ziggo ip is picked up instead of the domain server ip but that is quite seldom.

Je kunt me ook een pm sturen in het Nederlands als je wilt.