Suddenly can't receive or send any mail anymore

Hi guys

I have an MiaB installation that worked fine during a week. But now I can’t send or receive mail.
What happened?

I pasted the last few lines of the mail.err log here:

Thanks in advance everyone!

Kriz De Logi

EDIT: // this is a mail I received from mailer-deamon (I don’t understand why there are other mail adresses that don’t have anything to do with my domains)

May 18 09:38:19 box opendkim[11783]: 08BC9A9A1A: key retrieval failed (s=mail, '' record not found

Looks like you are missing a DNS entry.

Also Out: 451 4.3.0 Error: queue file write error Means you have a permissions issue in the server.

I checked the DNS entries and all seem correct. Only the web entry is not set because I don’t want MiaB to handle my web requests.

Okay, I got it working again, but now I see my mail gets sent or received very slowly, so I had a look at mail.log and was surprised to see some unusual traffic. How can I block this?

May 19 10:29:16 box postfix/smtp[23191]:[]:25: TLS cipher list "aNULL:-aNULL:ALL:!EXPORT:!LOW:+RC4:@STRENGTH:!aNULL:!RC4"
May 19 10:29:16 box postfix/smtp[23191]: looking for session smtp& in smtp cache
May 19 10:29:16 box postfix/tlsmgr[25925]: lookup smtp session id=smtp&
May 19 10:29:16 box postfix/tlsmgr[25925]: read smtp TLS cache entry smtp& time=1526718520 [data 1626 bytes]
May 19 10:29:16 box postfix/smtp[23191]: reloaded session smtp& from smtp cache
May 19 10:29:16 box postfix/smtp[23191]: SSL_connect:before/connect initialization
May 19 10:29:16 box postfix/smtp[23191]: SSL_connect:SSLv3 write client hello A
May 19 10:29:16 box postfix/smtp[20413]:[]:25: subject_CN=*, issuer_CN=thawte SHA256 SSL CA, fingerprint=3B:6A:BE:47:F5:F2:F9:20:1F:EE:AC:6F:DA:4C:4E:96, pkey_fingerprint=D5:8F:4C:F4:22:49:F4:51:2B:01:11:03:8C:A4:61:3B
May 19 10:29:16 box postfix/smtp[20413]: Trusted TLS connection established to[]:25: TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)
May 19 10:29:16 box postfix/smtp[22254]: 82BC1AD644: host[] refused to talk to me: 421 cox blocked - Error Code: CDRBL - Refer to Error Codes section at for more information.

What are these domains exactly doing on my server?

Thanks in advance

Ok. I just restarted everything over again. Hoping that everything becomes secure

Is your domain or ?? Or are you hosting mail for both domains on your box?

I’m hosting both domains. Also and