Deliverability Glossary

We throw around a lot of acronyms and email deliverability terminology. So we've decided to create a glossary or "ABC's", if you will, of email deliverability terms to make things easier.

A is for A/B Testing: A useful way to test different versions of your email to see which one drives more engagement with recipients.

B is for Blocklist/Blacklist: A list of IP address or domains that are known to send spam. Used by ISP's and other providers to determine whether they should allow messages from you.

B is for Bounce (hard and soft): An automated message from an email client letting the sender know that the message has not been delivered to the recipient. There are two types: Hard bounce: A hard bounce occurs when an email is rejected by the receiving mail server because the recipient’s email address is invalid, disabled, inactive or otherwise permanently unavailable. Soft bounce: A soft bounce is a a temporary email delivery failure. They occur when the recipient's mail server returns that it cannot, at this time, receive emails on behalf of the recipient.

B is for BIMI: How your brand is represented and displayed in an email inbox, or essentially your brand logo.

B is for B2B and B2C: Transaction or business that is conducted business-to-business or business-to-consumer.

B is for Batching: The art of sending out your messages in groups rather than individually. Often used to prevent rate-limiting from email clients.

B is for Behavioral Email: An automated email that is sent out based on a user action (event in Vero).

C is for Conversion: When a customer carries out an intended action that is set as a goal on a campaign. Ie. added_to_cart, upgraded_plan. More on types of conversions here.

C is for Click Rate: When a recipient clicks any link in an email.

C is for Complaint: When a user lets their email client know they are unhappy with receiving messages from you and no longer want to.

C is for CNAME (Canonical Name): A way to alias one domain name to another name. It offers flexibility with managing domain and subdomain redirection. Also vital for click tracking.

C is for CASL: Canada’s spam law.

C is for CAN-SPAM: U.S. spam law (not particularly useful).

C is for Complaint: When a user let's their email client know they are unhappy with receiving messages from you and no longer want to.

D is for Domain Warming: Gradual sending process to build up your domain reputation to stay friendly with email clients.

D is for DMARC (Domain-based Message Authentication, Reporting and Conformance): An email authentication record that allows domain owners to control and protect their domain from unauthorized sending like email spoofing.

D is for DNS (Domain Name System): What us in the email world fondly call the “phone book of the internet.” Essentially it translates domain names into “computer language” so that databases can understand it.

D is for DKIM (DomainKeys Identified Mail): A standard record for email authentication. Its most important role is making sure that the email being sent was indeed from the real owner of that domain.

D is for Delivered: The step after an email has been sent and the sending provider (ie. Mailgun, Sendgrid) confirms successful delivery to the recipient server.

D is for Deliverability: What we preach about every day! The ability to deliver your message to the recipient’s inbox.

D is for Dedicated IP: An IP that is exclusively assigned to a specific domain.

D is for Double Opt-in: When a user signs up to an emailing list through a form and is then sent an email that includes a link that they must click to confirm their subscription.

E is for Engagement: A common measurement used in marketing. When the recipients of your messages take action like opens and clicks to express their interest in your content.

E is for Email Hygiene: Keeping your email recipient list clean of spam traps, inactive, and bad addresses that impact your deliverability negatively.

E is for Email Authentication: Making sure that an email domain actually belongs to you.

F is for Failed: When an email fails to reach a recipient mailbox due to delivery issues like bounces, blocklists, and other SMTP server errors.

F is for Feedback Loop (FBL): A special service offered by many email clients allowing you to stay on top of spam complaints made by their users on your email campaigns.

G is for GDPR (General Data Protection Regulation): The EU's privacy and security laws that strongly protect personal information. This is the toughest data privacy legislation in the world.

G is for Google Postmaster: The mecca for Gmail's sender guidelines and requirements to keep them happy as an email client. Also a great place to have more detailed information about delivery errors and spam rates with Gmail.

H is for Honeypot: an intentional inactive email address that has never opted into anything and is used to catch spammers.

I is for Inboxing: The goal of having your emails reach the end of the rainbow, aka the recipient’s inbox.

I is for ISP (Internet Service Provider): In the email world this means companies like Gmail, Yahoo, Hotmail, etc.

L is for List-Unsubscribe: An email header generated by email clients (ie. Google, Yahoo) that gives recipients a chance to easily unsubscribe from an email list.

M is for MX Record (Mail Exchange Record): Necessary for delivering email to a particular mail server

O is for Open Rate: When a recipient (or email client) opens your email.

O is for Opt-in: When a user gives explicit permission to be added to your mailing list and be sent promotional or other types of email.

P is for Phishing: A malicious email message used to deceive a recipient into divulging personal information.

Q is for Quarantine: An added layer of some email security systems that monitors incoming emails for malicious content and may hold an email temporarily before releasing it to the recipient mailbox.

R is for Rate Limit: Every email client (ie. Google, Yahoo) has a limit of the number of emails it will accept from a specific domain over a time period. They have a generic base level rate but then will adjust this based on the company's deliverability reputation, volume of emails they send and speed at which they send.

R is for Return Path: The domain or header that is used in order to track bounces and determine where that information is sent.

S is for Seedlist: A small list of emails used to send campaigns to in order to test the inboxing rate.

S is from SNDS (Microsoft Smart Network Data Services): The portal for Microsoft’s sender guidelines and requirements to maintain good sending reputation with them. Here you can also find more delivery error and spam rate details.

S is for Suppression: when an email account is no longer reachable and should not be sent to.

S is for SPF (Sender Policy Framework): A domain record also used for email authentication which ensures the domain is allowed to send from that IP(s).

S is for Spamhaus: The big daddy of all blocklists.

S is for Sent: When the email and list of recipients has been sent to the delivery provider. ie. Mailgun, Sendgrid.

S is for SMTP error (Simple Mail Transfer Protocol): A specific error given by mail servers that give insight into why a message was not delivered successfully.

S is for Shared IP: IPs that are part of an IP pool shared between various sender domains.

S is for Segmentation: Creating groups (segments) of email subscribers based on select criteria, behaviours, and interests.

S is for Spam Traps: Real email addresses (also a type of honeypot) that are used by ISPs and other providers to identify if senders are sending spam and have good list hygiene.

S is for Sunset Clause: A segmentation tool to remove long-term unengaged users from your list. Ie. Has not opened or clicked any campaign in 60 days.

T is for Transactional Email: An automated email that is sent out based on a user action (event in Vero). Transactional email content contains critical information including transactions, privacy and terms updates, and password resets. These are sent to all recipients, regardless if they are unsubscribed or not.

U is for Unique Click: The amount of times a URL was uniquely clicked by a user. If a user clicks on the same link 5 times, this is considered one unique click.

U is for Unsubscribe: An action taken by a user to opt-out of receiving messages from you going forward.

V is for Vero: Obviously!

W is for Whitelisting: The practice of asking your email client to add approved senders in order for their messages to reach your inbox.