Reducing sending spamscore
Adding a DMARC record
DMARC is a system that adds some rules for DKIM and SPF to give remote servers a better idea of what your intention is for messages that fail those 2 systems. It doesn't really do anything other than clarifying the desired actions to be taken by remote servers, but should lower your spam score in some cases. Be sure that your SPF TXT value contains "-all" (not ~all) and that you have DKIM setup before proceeding.
To add a DMARC record when using the Evolution skin:
- Navigate to "DNS Management"
- Click "Add Record"
- For "Record Type", select "TXT"
- TXT Record Type, select "DMARC"
- Enter your email into the "Aggregate Email (RUA)" field: email@example.com
- Click "Add"
For other skins, like the "Enhanced" skin, to add a DMARC record, go to your domain's DNS Management interface and add the following TXT record:
_dmarc TXT "v=DMARC1; p=none; sp=none; rua=mailto:firstname.lastname@example.org"
Be sure to include the whole thing in "quotes".
The email address email@example.com will sometimes be sent reported spam messages by larger providers. Not all services will email this address, but it's handy if a client using a large email provider clicks "this is spam" for a given message because you'll then be sent that message. Upon receipt, you can determine if someone at your domain is spamming or spoofing, or if the recipient incorrectly labeled the message as spam (at which point, you'd probably want to remove that recipient from your mail-out since they likely don't want it).
rua=mailto:email portion is not mandatory if you don't want to get these emails.
You can change the values as desired, as per the DMARC specifications.
Google's DMARC guide can also be useful for constructing your DMARC record.
How to automate adding a new DMARC for new domains
If you like the above setup, and you want to automate its addition to all new DNS zones, you can run the following:
cd /usr/local/directadmin/data/templates/custom cp ../dns_txt.conf .
and then add the record you want to the bottom of the
custom/dns_txt.conf by running this command:
echo '_dmarc="v=DMARC1; p=none; sp=none; rua=mailto:spam-reports@|DOMAIN|"' >> dns_txt.conf
Keep in mind that this assumes that you have a 'spam-reports' email account created already.