Setting up DKIM and other DNS records for my mail server with external DNS

Question

ello,

I'm trying to set up a 3rd party domain for my mail server and so far I've struggled making it out of the spam folder for my sent messages. And It's a whole other story with hotmail which blacklists my whole server. My DNS records are externally hosted on another Registrar and so far I've managed to pass some tests (SPF tests) when sending mails to: check-auth@verifier.port25.com. However, I cannot seem to pass the DKIM test where I get permerror. Here's what I did to set it up, I went to cpanel > Email > Authentication. and copied the DKIM record as shown on the page to a DNS entry on my registrar:

default_domainkey @ example.com TXT ... Here's the DKIM report on auth25:

----------------------------------------------------------
DKIM check details:
----------------------------------------------------------
Result: permerror (invalid key: error reading public key: 139806656485120:error:0D07209B:asn1 encoding routines:ASN1_get_object:too long:asn1_lib.c:142:;139806656485120:error:0D068066:asn1 encoding routines:ASN1_CHECK_TLEN:bad object header:tasn_dec.c:1306:;139806656485120:error:0D07803A:asn1 encoding routines:ASN1_ITEM_EX_D2I:nested asn1 error:tasn_dec.c:381:Type=X509_PUBKEY;)
ID(s) verified:
Canonicalized Headers:
message-id:<8e56704aed7b951ff8fadb1233971857@example.com>'0D''0A'
subject:TEST'0D''0A'
to:check-auth@verifier.port25.com'0D''0A'
from:salwa.fawzi@example.com'0D''0A'
date:Fri,'20'04'20'Dec'20'2015'20'10:56:30'20'+0100'0D''0A'
content-transfer-encoding:7bit'0D''0A'
content-type:text/plain;'20'charset=US-ASCII;'20'format=flowed'0D''0A'
mime-version:1.0'0D''0A'
dkim-signature:v=1;'20'a=rsa-sha256;'20'q=dns/txt;'20'c=relaxed/relaxed;'20'd=example.com;'20's=default;'20'h=Message-ID:Subject:To:From:Date:'20'Content-Transfer-Encoding:Content-Type:MIME-Version;'20'bh=q5cyARPl5zX/knmvCnEy11G7/r6gcljJ44qrvv5DErY=;'20'b=;

Canonicalized Body:
TEST'0D''0A'


DNS record(s):
default._domainkey.example.com. 86400 IN TXT "v=DKIM1; k=rsa; p=MIIBIjANBgkqhkiG9w0BAQEFAAOCAQ8AMIIBCgKCAQEA+INdfCMRWPx4Kr2vYS+S11VcN/7GGUBt9ZSgEJQCtesw0v4xFlNjA2N1N+ymshVZOPB76dhzd7CWb2YTYiUl5TjzM69Dp15KSDu5kQNwX/MaIHSNkWlnz+3AcdRG5rCwDxKkWiPlTDREz8bFdIY1+3UZbetZhq70+NQPYjMZHn69KzOnNrYraZ6es5nVDFVJi"

If anybody had experience on setting up Mail Servers on Cpanel/WHM I would really appreciate their help.

Answer 1

This:

MIIBIjANBgkqhkiG9w0BAQEFAAOCAQ8AMIIBCgKCAQEA+INdfCMRWPx4Kr2vYS+S11VcN/7GGUBt9ZSgEJQCtesw0v4xFlNjA2N1N+ymshVZOPB76dhzd7CWb2YTYiUl5TjzM69Dp15KSDu5kQNwX/MaIHSNkWlnz+3AcdRG5rCwDxKkWiPlTDREz8bFdIY1+3UZbetZhq70+NQPYjMZHn69KzOnNrYraZ6es5nVDFVJi

is not a valid DKIM public key. How did you generate this value?