Message detected as spam - heuristic check

Hi.
I've started to receive messages:
"5.7.1 Message refused by Heuristic check. This email has been rejected. The email message was detected as spam."
What can I do about it?

Earlier I received "Our system has detected that this message is likely unsolicited mail. To reduce the amount of spam sent to Gmail, this message has been blocked"
But I managed to repair it by setting DKIM:
"x._domainkey TXT "v=DKIM1; k=rsa; p=MIIB..... etc"

But now this heuristic problem.
What can I do?

Who has sent the message that the mail was refused by the heuristic check? Likely only the administrator of the sever sending you that message can tell you why it was refused, because heuristic filters are self-modifying.

Jeff

Email was sent from [email protected] to [email protected]

Your reply doesn't directly answer my question. If the message that the email failed a heuristic check was sent by mutyzm.pl, and if that's your domain on your server, then you need to figure out what you're running that runs that heuristic check, and whitelist the domain through it, or fine tune it so it won't find your messages to fail the check.

If the message that the mail failed a heuristic check was sent by Yahoo, only they can tell you why, and/or how to fix it.

Jeff

The problem continues.
Heuristic check was fixed (I guess) because now I receive when I send from [email protected] :

This message was created automatically by mail delivery software.

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:

[email protected]
SMTP error from remote mail server after end of data:
host gmail-smtp-in.l.google.com [2a00:1450:4013:c00::1a]:
550-5.7.1 [2001:a10:e0:0:21e:c9ff:fead:411e 16] Our system has detected
550-5.7.1 that this message does not meet IPv6 sending guidelines regarding PTR
550-5.7.1 records and authentication. Please review
550-5.7.1 https://support.google.com/mail/?p=ipv6_authentication_error for more
550 5.7.1 information. l42si51320555eef.58 - gsmtp
"

DNS zone:
"
ftp A 194.181.16.248
localhost A 127.0.0.1
mail A 194.181.16.248
poczta A 194.181.16.248
pop A 194.181.16.248
smtp A 194.181.16.248
tancula.net. A 194.181.16.248
www A 194.181.16.248
www.poczta A 194.181.16.248
tancula.net. NS ns1.e-poltel.com.
tancula.net. NS ns2.e-poltel.com.
mail MX 10
248.16.181.194.in-addr.arpa. PTR tancula.net.
_domainkey TXT "o=~"
tancula.net. TXT "v=spf1 a mx ip4:194.181.16.248 ip6:2001:a10:00e0:0:194:181:16:248 ~all"
x._domainkey TXT "v=DKIM1; k=rsa; p=MIIBIjANBgkqhkiG9w0BAQEFAAOCAQ8AMIIBCgKCAQEAnBYLGPsTMjAl2f0H1f4tSTUIrNc6ADDgBGoBKgMfEaX0DKHqlvx1/cJP9jCuYEgovaJTKBzoWFgEwrJ3KJsHu5t
FsR6VJ2BZuc+1unys7dFVUhDDEIptqc+hBV7GbqF5ncfFoWKPBltAHh7MmPsLU9KVfmwEWBZuUBsbSBtm5qU5IhKdVYkCZnkTeLDGdSQXHDZ9AznBQIE1qHZygwIuIfXXj/jHyKWc9JRwM/o4WE9wT
m1unt5KTOp++b+npQ/yCbP9+kt1HQzYyelCiEs7V6EFw0JbtYjzJRMVgaEnwlc2kO2tgf7XuTulQW9/OuMhvAekYSC8F2nU/H9OjgDQHwIDAQAB"
localhost AAAA ::1
}
"


Mail server IP 194.181.16.248 - server.e-poltel.com
What can I do to FIX this problem.

Email was sent from [email protected] to [email protected]

Click to expand...

But you show a gmail server in the mix. Is the server you use to send mail running DirectAdmin? Is the server receiving the mail running DirectAdmin?

Jeff

I'm sending mail from DirectAdmin.

I keep receiving:
"This message was created automatically by mail delivery software.

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:

[email protected]
SMTP error from remote mail server after end of data:
host gmail-smtp-in.l.google.com [2a00:1450:4013:c01::1a]:
550-5.7.1 [2001:a10:e0:0:21e:c9ff:fead:411e 16] Our system has detected
550-5.7.1 that this message does not meet IPv6 sending guidelines regarding PTR
550-5.7.1 records and authentication. Please review
550-5.7.1 https://support.google.com/mail/?p=ipv6_authentication_error for more
550 5.7.1 information. l4si58844092eew.251 - gsmtp
"

I checked and I have installed IPv6 on my system.
But still gmail is rejecting me.

Have you checked to make sure your rDNS is properly assigned? What do you get when you do a lookup of rDNS for yor IPv6 address?

Jeff