Sender Requirements

These are the requirements senders must meet so their mails are successfully delivered to their subscribers.
You will find that most of these match long-standing best practices eg. as outlined in M3AAG's Best Common Practices.
With mail providers facing increased challenges to protect their user's inboxes, what was onces a set of best practices has become a set of hard requirements.

Most of these requirements are fullfilled by Dropsolid on the infrastructure level, but some requirements have to be fullfilled by owners of the Marketing automation (Mautic) product (or their technical contacts).

Requirements for Mautic owners

1. Set up the provided DNS records to provide proof you're sending valid mails.

To give the necessary guarantees to the receiving mail servers (Google, Yahoo, Outlook, ...) that the email is from a valid source, some proof needs to be given.

This is done by signing the emails, and providing the needed info for mail servers to validate and take the correct actions.
This process consists of the following steps:

1. Dropsolid ensures that the mails are signed, and will provide you the needed DNS records that need to be defined.
2. As an owner you need to ensure the needed DNS records are added or combined with existing records. When in doubt, please reach out to your IT departement or domain name provider.
3. Once the records are added, Dropsolid does the necessery validation and reports back if issues are detected.

For every sending domain linked to your Marketing automation instance, we will provide the following DNS records:

• 2 CNAME records that provide the needed info for the DKIM mail signing
• a TXT record with the SPF details.
• an A record to link the sending IP to the sending domain for the PT
• a TXT record with the DMARC details.

overview of the used concepts and terms

• DomainKeys Identified Mail (DKIM) uses asymmetric encryption to sign and verify your email.
• Sender Policy Framework (SPF) allows you to list all the IP addresses that are authorized to send email on behalf of your domain.
• DMARC (Domain-based Message Authentication, Reporting & Conformance) is a standard that builds on SPF and DKIM. DMARC communicates a policy to mailbox providers letting them know what they should do when they receive an email that fails an SPF, DKIM, or SPF and DKIM check purporting to be from your domain (possibly spoofed).
• Reverse DNS (PTR) links the sending domain to the used sending IP address, and the other way around.

2. Keep spam rates reported in Postmaster Tools below 0.3%

Senders will need to maintain their spam complaint rate below 0.3%, this can be tracked and measured in Google Postmaster.
For this reason, we recommend you sing up for a Google Postmaster account today, if you don't have one already.

If the spam rate starts to get near to 0.3%, take a look at these tips to reduce your complaint rate.

3. For subscribed messages, include a clearly visible unsubscribe link in the message body.

Your Mautic email templates should contain an unsubscribe link that is clearly visible. Head over to the "Emails" tab, and within your templates, ensure that you include an unsubscribe link that's easily visible. Ideally this should be connected with a Preference Centre in Mautic, which allows the user to set their preferences or completely unsubscribe.

Next to the unsubscribe link in the email template, we take care of providing a second method for subscribers to easily remove themselves from your mailing list. We add a List-Unsubscribe header, which will insert an “unsubscribe” button, or link, next to the From address at the top of your email.

Requirements we take care of for you

Besides configuration and validation of the sending infrastructure and the requiremens where we need input from you, we also take care of following (technical) items.

This information was sourced, in part, from Sendgrid's documentation and blog posts.

Format messages according to the Internet Message Format standard (RFC 5322)

RFC 5322 is an Internet standard that defines the correct format for email messages. That covers the message headers, body, and attachments.

Our solution already blocks sending emails that don’t follow RFC 5322 compliance guidelines, such as if a ‘from header’ is not included. Look through the Internet Messaging Format and confirm each component (envelope, body, header, and attachments) meets the requirements.

For direct mail, the domain in the sender's From: header must be aligned with either the SPF domain or the DKIM domain.

You need to pass DMARC alignment to satisfy this requirement. The domain you include in your From: header must align with either the SPF domain or the DKIM domain. Alignment refers to the verification that the DKIM and SPF signatures in your email headers align with the domain you've authenticated your SendGrid account with.

In a simplified answer, you need to ensure the “from” address you are specifying in the “From: header” matches the domain you authenticated with SPF or DKIM. Beyond the simplified answer, there is strict alignment and relaxed alignment and several scenarios (including the use of subdomains) you need to consider. Thankfully, Google has an entire blog post on explaining those scenarios in great detail.

For subscribed messages, enable one-click unsubscribe and include a clearly visible unsubscribe link in the message body.

On the Mautic side, the email templates should also contain an unsubscribe link that is clearly visible. More on that in the 'Requirements for Mautic owners' section above.

Besides that, one-click unsubscribe (list unsubscribe) provides a second method for subscribers to easily remove themselves from your mailing list. The List-Unsubscribe header will insert an “unsubscribe” button, or link, next to the From address at the top of your email.