From Sent to Delivered


Email security by your ESP (in this case APSIS One) is a vital step in securing the legitimacy of your email, and its deliverability.

  • Once the email is sent, security measures are put in place. Has the email header been spoofed in the hopes of tricking the recipient? Is it a phishing email? Authentication measures will identify malicious emails and place them in the junk folder.


Authentication protocols perform checks to eliminate email forgeries, ensures that messages are unaltered in transit, and determines the authenticity and ultimately whether to accept or reject the email.

  • If you can only do one thing to improve your deliverability, you should authenticate your emails. Sender Policy Framework (SPF - automatically in place with APSIS One), DomainKeys Identified Mail (DKIM), and Domain Message Authentication Reporting & Conformance (DMARC) are protocols that tell mailbox providers that you are who you say you are.


Email deliverability is largely determined by sender reputation. There's a few things you can do to create and maintain a decent sender reputation.

  • Choosing a good ESP (Email Service Provider), as well as a good ISP (Internet Service Provider) is essential for your business and your email deliverability. Good connection, speed, and reliability, all have the power to affect your sender reputation.

  • A poor IP reputation can mean that emails sent from that specific IP ends up being flagged as spam. Here at APSIS One, we have a dedicated Delivery team who monitor all aspects of IP addresses, so you don't need to worry about having a bad IP address.

  • Unless you're sending bulk emails to spam traps, it's unlikely your server will be blacklisted. However, taking care of your Profiles and avoiding spam traps will ensure you don't get blacklisted. Ask your recipients to whitelist your communications so you are safely added to their address book or safe sender list.

Blocking and Missing

Before reaching their final destination, emails can be blocked by the recipient's server.

  • Sending emails to an Unknown User, or an email address that has never existed, been abandoned by the user, or terminated by the mailbox provider, can directly affect your sender reputation, and can prevent emails from landing in recipient's inboxes. By maintaining good list hygiene, this problem can be avoided.

  • Avoid ending up in the spam folder! Remember to include an unsubscribe link, always use Double Opt-in in your communications, and send to Profiles who have a history of engagement with your emails - creating a Segment to target those Profiles who have clicked on your CTAs is a great way to increase and maintain engagement.


Emails can bounce for a variety of reasons: monitor your email reports to see if and why your email has bounced.

  • Email sent to an unknown address will result in a bounce. The same goes for if the recipient's mailbox is full, if the receiving email server can't be found, or is temporarily unavailable.

Next Step

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