Setup DKIM

Hi,

I'm facing with DKIM issue.

I want to send via my program DKIM (private key is signed in my message), but after check dkim is not valid.

I got:
We were not able to retrieve your public key.
Please ensure that you inserted your DKIM TXT DNS record on your domain xxx.com using the selector mailer._domainkey.

I think ubuntu not find TXT DNS recor mailer.domainkey. This is ok.

Maybe I need installed something on ubuntu?

Do you have a DKIM TXT DNS record for your domain name? DKIM requires that. The error is saying it can't find it.

I think ubuntu not find TXT DNS recor mailer.domainkey. This is ok.

No, it's not. It's not an ubuntu issue.

Yes, I have DNS correct setting 100%. Also works on mxtoolbox dkim and other websites like mxtoolbox.

I tried on windows server for testing and also works. I think is problem on Ubuntu...

OK. What "program" are you using to send email with that's giving you an error.
Please copy/paste the exact error you're getting. Use [code] tags.

I don't have any errors. I used my own program, but program work because I tried on Windows Server. First time after check on Windows Server was problem with antivirus. I disabled and works.

DomainKeys Identified Mail (DKIM) is a method for associating a domain name to an email message, thereby allowing a person, role, or organization to claim some responsibility for the message.
The DKIM signature of your message is:

v=1;
a=rsa-sha256;
bh=0d5E9wADbfDioMCEjL2ZVoc9bokjAXjxN3APxiFF9NA=;
d=xxx.com;
h=Message-IDate:Subject:From:Reply-To:To:MIME-Version:Content-Type:X-Acelle-Subscriber-Id:X-Acelle-Sending-Server-Id:X-Acelle-Message-Id:X-Acelle-Customer-Id:X-Acelle-Campaign-Id:Precedence:List-Unsubscribe;
i=@xxx.com;
s=mailer._domainkey;
t=1545163510;
b=iP6uk4OPKgYPR8esmPJcaTNBguLCVpA2mmJngeF+DHRjGfaS7bfkQzpq6JlPqBTgVeTd+qhtutuZKGEoyHzDNBLqdydOZau56B tf9sQoFaOTbTnIvopE+jbMjaWLSIDV1261rHxB5DeKSHbziHiwIYipRPoF6cd0C0xdWq5qOhk=
We were not able to retrieve your public key.
Please ensure that you inserted your DKIM TXT DNS record on your domain xxx.com using the selector mailer._domainkey.
If you recently modified your DNS, please be patient and test again your Newsletter in 12 hours, it may take some time for the DNS to be propagated