This post is the first in a four part series on best practices for email marketing. Want to learn more? Download our ebook here.
What is email deliverability?
Email deliverability, usually expressed as a percentage, measures how many emails actually make it into the inbox. Email deliverability includes anything that is involved with the delivery of your emails, from the sending tools to all the intermediate steps (ISPs, MTAs, etc.). Proactive deliverability management ensures successful email marketing while complying with the laws that govern email.
For instance, emails can end up in a recipient’s junk folder or they can be blocked by an Internet Service Providers (ISPs) (without any warning or notification). Sometimes the email bounce metric reflects only a small proportion of all the emails that don’t get delivered.
When sending a high volume of emails, the way they are delivered is crucial in terms of how they will be interpreted by ISPs and anti-spam filters.
11 key terms and definitions
- Blacklisting – Blacklisting services constantly monitor the Internet for spammers. When a sender IP address is blacklisted (that is, it has been identified as spam) the emails sent from that address may not be delivered.
- ESP – An Email Service Provider (ESP) is an organization providing email services, usually focusing on email marketing.
- Feedback loop – These are feedback processes spanning different organizations where mailbox providers forward their customers’ complaints to the senders’ organizations, often ESPs.
- ISP – An Internet Service Provider is an organization providing services for accessing or using the Internet.
- Spam trap – These are email addresses created and maintained by ISPs and third-party blacklisting companies with the sole purpose of detecting spam senders. Using such addresses in a mailing can harm your reputation and land you on a list that identifies you as a sender of spam messages. That alone is a good reason to avoid purchasing or renting marketing lists.
- DNS – DNS is an abbreviation for Domain Name System, a system for naming computers and network services. DNS naming is used in TCP/IP networks, such as the Internet, to locate computers and services through user-friendly names.
- Infrastructure – In the context of this document, an email marketing provider that covers all the hardware, network and software infrastructure aspects needed to send millions of emails daily with the highest deliverability rates.
- IP address – An IP (Internet Protocol) address is a numerical label assigned to each
device participating in a computer network that uses the Internet Protocol for communication.
- Soft bounce – When a system attempts to delivery an email to a legit address multiple times over a given period of time without success, that address is defined as a “soft-bounce.”
- Hard bounce – When a system attempts to delivery an email to an address that is permanently faulty that address is defined as a “hard-bounce.”
- SPF – Sender Policy Framework (SPF) is an email validation system designed to detect email spoofing. By using SPF the owner of an Internet domain can specify which computers are authorized to send email with sender addresses in that domain.