Hello @PentwaterYachtClub ,
The first thing you'd want to check for is to make the the contact's email address is both accurate and subscribed to you. Once you've confirmed that, the next steps would be to start looking into making sure your delivery is as optimized as possible.
Here are some general best practices for deliverability. Deliverability can have a lot of variables, from elements on our side, on your side, on the recipient's side, and in their email system company's side. It's also a good idea to set up self-authentication since you're sending using an address with your own, unique domain. With all the delivery gatekeeping and anti-spam/malware safeguards in place, it's necessary for businesses using an ESP to have this in place.
If you'd like to learn more about safelisting, and what it entails:
Safelisting domains in a security system
Safelisting email addresses in an email client or security system
If you're wanting more in-depth, specialized insight on your current deliverability, it'd be worth speaking with one of our Deliverability agents.
See also:
Email Authentication FAQ
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