First, we must make a distinction between types of emails you will be sending. This is important because the health of the IP addresses that you are sending from determine the crowd that ESPs recognizes you as being a part of. When you send password reset messages or announcements about accounts, these messages should be on separate, dedicated IPs because those that you send to affect the health of each IP. These are called transactional emails and are different than regular emails such as newsletters, invoices, or reminders. Our ultimate goal is to protect both types of sending by separating the two. Next, we recommend using Google’s reCAPTCHA feature to cut down on automated bot signups and also using a real-time API on your lead forms to verify ownership before sending to your list.
There are also three aspects of a sending profile that require authentication in order to make sure you isolate any sending issues before reviewing list hygiene.
Four more aspects of sending that you should be aware of are the DNS Provider Usage, CDN, PTR records, & FDLs. When your Domain Name Service (DNS) is easy for an email sender to find and you have properly confirmed where hostnames point to records (PTR) through reverse DNS lookups, you create a more efficient message process for ESPs and they will reward you by prioritizing your email in your recipient’s inbox. You can add to this efficiency by setting a Content Delivery Network (CDN) which will cache versions of content to provide faster load times, ISP prioritization, DDOS & advanced firewall protection. Complaint Feedback Loops (FDLs) are also incredibly important because you must give recipients will inevitably complain about your sending practices and you will be notified of those complaints when ISPs receive them when you set this service up.
Also, setting up abuse@ and postmaster@ addresses from your sending domain will add to this effort of awareness by clearly defining a path for ISPs to follow in order to notify you of complaints or red flags. With all of this work you have put into building a healthy sending domain, we certainly recommend using DNSSEC to protect your DNS lookups from being hijacked. It’s not required, but let’s get you all the extra credit that we can with ESPs.