DKIM, SPF, DMARC, link branding and sending domain verification

Why is it important to set up the DNS records for sending correctly? What is DKIM, SPF or link branding? You will find that out and much more in this article.

Why is it important to secure your e-mails properly?

Over the past years the volume of sent e-mails has risen rapidly. With this growth, however, came a rise in unsolicited e-mail communication, known as SPAM. It is said that up to 80% of all e-mails sent in the world in a single day is SPAM.

Mailbox providers such as Gmail.com or Seznam.cz (also called ESPs, from Email Service Provider) try to fight SPAM in every way they can. It makes sense. They simply do not want you to find dozens of e-mails in your mailbox every day that do not belong there and that you do not want. So they introduce technical measures that you, as a sender of bulk e-mails, have to follow for your e-mails to reach the mailboxes of individual recipients.

These technical measures are the SPF technology and the DKIM technology. Both of these tools serve as prevention against SPAM senders and help mailbox operators verify the sender and the content of an e-mail better.

Besides setting up the SPF and DKIM records, your sending domain has to be verified as well. After the verification, the e-mail header (the technical part that is not visible but holds important data for the mail servers receiving the mail) uses a main sending e-mail (smtp mail from) that contains your domain. This way many more of your e-mails are delivered into the primary folders and do not end up in the promotions or junk mail folders.

Using these tools therefore shows very favourably in better deliverability of your e-mails and consequently in your overall results.

The security of your e-mails

It is not "only" about good delivery of sent e-mails, though. All of these elements also serve to secure your sent e-mails and protect your sending domain from possible abuse. By applying these security elements (DKIM, SPF and DMARC) you make sure that e-mails which merely try to look like e-mails sent by you, or rather by your domain, are blocked or deleted before they reach the recipients' mailboxes.

DMARC

DMARC (Domain-based Message Authentication, Reporting & Conformance) lets the sender specify how e-mails that were not verified with the SPF and DKIM records should be handled.

The setup is done on the sending domain by setting the relevant DNS records. This record specifies how to handle e-mails that did not pass the SPF and DKIM verification. At the same time you can set an e-mail address to which reports about the checks performed and their results will be sent by the mailbox providers receiving your e-mails.

How to set up a DMARC record?

You set this record up using the specification you find by clicking the link below this paragraph. It is an independent technology which, through the DMARC record placed in the DNS records of your sending domain, monitors sent e-mails containing your domain regardless of whether your e-mails are sent through Quanda, Outlook or any other e-mail sending program or service.

More about DMARC

The SPF record

SPF (Sender Policy Framework) is an e-mail validation system serving as a defence against SPAM. Its principle is that it verifies the sender's IP address. SPF lets administrators specify which computers may send mail from a given domain. The administrator has to create an SPF record (or a TXT record) in the DNS (Domain Name System).

By setting this record up you effectively authorise the server that sends mail in your name to do so. The servers receiving your e-mails can then verify that the e-mails you send them are sent by a server you authorised, and that it is not someone merely pretending to be you and abusing your domain to spread their own messages.

More about SPF

The DKIM record

This is a technique which, using asymmetric encryption, can verify in a guaranteed way that a particular e-mail (including its unchanged content) was sent from the domain contained in the e-mail.

With this setting your outgoing e-mails are digitally signed. The servers receiving your e-mails therefore have certainty that these are your messages, genuinely sent by you. This setting helps improve your reputation as a sender of bulk e-mail messages very intensively, and it also helps mailbox providers easily recognise the author of the e-mails and their content.

More about DKIM

Sender verification

By setting up these CNAME records you allow Quanda to send e-mails in your name (the SPF record is set up and the sending domain is verified). The records marked "s1" and "s2" are the so called domain keys (DKIM). They serve to verify the sender. All of these records significantly increase the credibility of the e-mails you send, improve their deliverability into primary folders and reduce the chance of your e-mails being delivered into junk mail or bulk folders.

Setting up links in e-mails (link branding)

By setting up these CNAME records you allow Quanda to use your domain for all the links in your e-mails. All of these records significantly increase the credibility of the e-mails you send, improve their deliverability into primary folders and reduce the chance of your e-mails being delivered into junk mail or bulk folders.

Sending from a dedicated IP address

The last part of the security package and the technical setup for precise delivery is sending your e-mail messages from your own dedicated IP address. In practice this means that you do not share an IP address within Quanda with other users for sending, and you have your own reserved IP address that only your e-mails leave from.

The benefits that sending from your own IP address brings:

fewer e-mails end up in the bulk mail folder, fewer e-mails are delivered into the junk mail folder;
more e-mails are delivered into the main folders;
fewer e-mails are filtered or blocked.

When is it worth using?