A/B Testing
A way to test which version of your newsletter performs better. You send version A to one group and version B to another (for example, two different subject lines). The version with more opens or clicks wins, and you can use it for the rest of your audience. This helps you make decisions based on real data instead of guessing.Analytics
Numbers and charts that show how your emails perform. Typical metrics include open rate, click rate, unsubscribes, and bounce rate. Analytics help you understand what your audience likes, what they ignore, and how to improve over time.Audience
The group of people who subscribed to your newsletter. Your audience is your community, whether it’s 50 readers or 50,000. It’s common to talk about audience and subscribers indistinctly.Authentication
The process of proving that an email is really sent by you and not by a spammer pretending to be you. It’s like putting your signature and stamp of approval on every message. The main tools for this are SPF, DKIM, and DMARC. LetterBucket handles this automatically for you.Blacklist
A list used by email clients and providers to block unwanted senders. If your domain or IP address ends up on a blacklist, your emails may go straight to spam or not be delivered at all. Good practices help you avoid this.Bounce
When an email can’t be delivered to a subscriber’s inbox.- Hard bounce: permanent problem, like an address that doesn’t exist. You must keep your email list clean to avoid sending to these addresses because it sends negative signals to email clients.
- Soft bounce: temporary problem, like a full inbox or a server issue. If you repeatedly try to send to an address and it keeps soft bouncing, you should remove it from your list.
Campaign
A single newsletter (or series of emails) you send to your audience. For example, your weekly newsletter is a campaign, as is a special announcement.CAN-SPAM
A US law that sets the rules for email marketing. It requires things like clear unsubscribe links and forbids deceptive subject lines. Even if you’re not in the US, respecting these rules improves trust with your audience.Click Rate
The percentage of readers who clicked a link in your newsletter. If 100 people open your email and 10 click, your click rate is 10%. Ideal range: 2–5% is common, 5–10%+ is excellent (depends on industry and audience engagement).CTR (Click-Through Rate)
Another name for click rate. Same concept.CSV File
A simple file format that looks like a spreadsheet. It’s commonly used to upload or download subscriber lists between platforms. It means “comma-separated values,” which is a way of formatting data.CTA (Call to Action)
The action you want your reader to take. Examples: “Read more,” “Subscribe,” or “Buy now.” A clear CTA helps readers know what to do next.Custom Domain
Your own branded web address for your newsletter, like yourname.com, instead of a generic link. This makes you look more professional and improves deliverability.Deliverability
How likely your newsletter is to land in the inbox instead of the spam folder. Good content, a clean email list, and proper authentication all boost deliverability.Delivery Rate
The percentage of emails that were successfully delivered (didn’t bounce). A high delivery rate shows your list is healthy. Ideal range: Aim for above 98%. Anything lower means you may have list quality or deliverability issues.DKIM (DomainKeys Identified Mail)
A system that adds a digital signature to your emails. It’s like sealing an envelope so the receiver knows it hasn’t been tampered with. It proves that the message really came from your domain. LetterBucket handles this automatically, so you don’t need to worry about it.DMARC (Domain-based Message Authentication, Reporting & Conformance)
A rule you set for your domain that tells inboxes what to do if an email fails SPF or DKIM. For example: accept it, send it to spam, or block it. DMARC also gives you reports about who is trying to send emails using your domain. We also handle this for you.DNS (Domain Name System)
The “phonebook” of the internet. DNS translates easy-to-remember names (like letterbucket.com) into the numerical IP addresses computers use to find each other. In the context of email, DNS is also where you set up important records (SPF, DKIM, DMARC, MX) that prove you’re a legitimate sender and tell inboxes how to handle your messages. If DNS is misconfigured, your emails may land in spam or not get delivered at all. This is configured automatically by us.Domain Reputation
Your sending reputation in the eyes of email clients like Gmail or Outlook. If you send wanted, engaging newsletters, your reputation improves. If people mark your emails as spam, it goes down. This is the most critical aspect of your deliverability.Double Opt-In
A process where subscribers confirm their email address after signing up. They get a confirmation email and must click a link. This ensures that only people who truly want your newsletter join your list.Email Client
The app or service people use to read their emails. Popular email clients include Gmail, Outlook, Yahoo Mail, and Apple Mail. Each client has its own way of displaying emails, which means your newsletter might look slightly different depending on where it’s opened. Some clients clip long emails, block images by default, or show the promotions tab separately from the inbox. Understanding how email clients behave helps you design messages that look good everywhere.Email List
The collection of subscribers who signed up to receive your newsletter. Your email list is one of your most valuable assets as a creator, because it’s an audience you own, not borrowed from social media platforms. Healthy email lists grow through opt-ins, shrink a little through opt-outs, and perform best when you practice good list hygiene. A clean, engaged list keeps your deliverability high and ensures your content reaches readers who actually want it.ESP (Email Service Provider)
A company or platform that helps you send emails to large groups of subscribers without getting blocked by spam filters. ESPs handle the technical side of deliverability, like authentication, IP addresses, and DNS settings, so you can focus on writing. LetterBucket is an ESP made for newsletters. Other tools can send newsletters too, but because they’re built for broader email marketing they can’t fine-tune things like newsletter design and deliverability the way we do.Footer
The section at the bottom of a newsletter. It usually includes your unsubscribe link, legal info, or contact details.From Address
The email address your readers see in their inbox when you send a newsletter (like hello@yourdomain.com).GDPR (General Data Protection Regulation)
A European law that protects personal data. It requires transparency, clear consent, and gives subscribers rights over their data. Even if you’re outside Europe, GDPR standards are a good trust practice.Header
The hidden technical part of an email that carries metadata like who sent it, where it came from, and authentication results. Most readers never see this, but inboxes use it to decide if your message is legitimate.HTML Email
An email built with HTML code, which allows for design, colors, images, and formatting. Most newsletters are HTML emails. Even if you just write plain text, it’s still built in HTML under the hood.Inbox
The place where received emails show up in your email client. When we talk about “landing in the inbox,” it means your email successfully avoided the spam or promotions folder and arrived where the reader is most likely to see it. For creators, the inbox is where you want every newsletter to land.IP Address
A unique number that identifies the server that sent your emails. It’s like your return address on a letter.Landing Page
A simple webpage with one clear goal, like collecting sign-ups for your newsletter.List Hygiene
The practice of keeping your email list clean by removing invalid, inactive, or unengaged subscribers. This improves deliverability.MX Record (Mail Exchange Record)
A special DNS record that tells the internet where to deliver emails for your domain. LetterBucket handles this for you.Newsletter
A recurring email you send to your audience. It usually includes updates, articles, or insights. It’s the main product most creators publish with LetterBucket.Open Rate
The percentage of subscribers who opened your newsletter. This is tracked using a tracking pixel. Ideal range:- 20–30% is typical.
- 30–40%+ is very good.
- Below 15% may signal subject line issues, spam folder placement, or list fatigue.