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.
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.
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.
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.
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.
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.
Bounces affect your domain reputation, so cleaning your list regularly is important.Ideal range: Bounce rate should stay below 2%. Higher rates mean your list needs cleaning.
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.
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).
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.
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.
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.
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.
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.
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.
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.
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.
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.
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.
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.
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.
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.
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.
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.
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.
A special folder in Gmail where marketing and bulk emails often land instead of the main inbox.The Promotions tab isn’t the same as the spam folder, your subscribers can still see your messages, but they may check this tab less often.Landing in Promotions is common for newsletters, especially if they contain lots of links, images, or promotional language. It doesn’t harm your deliverability, but you’ll usually get lower open rates compared to landing in the main inbox.That said, in practice there’s a big difference: emails in Promotions usually get lower open rates because many readers don’t check this tab as often as their main inbox.
The name that appears in the inbox as the sender, like “John Doe”.Your sender name is often the very first thing a subscriber notices, even before the subject line. It plays a huge role in whether someone decides to open your newsletter.Many creators use their personal name (“Sarah Johnson”) or a mix of personal and brand (“Sarah from TechNotes”) to make the email feel more trustworthy and human. Using just a brand name can sometimes feel cold or impersonal, while using only a first name may confuse readers if they don’t immediately recognize you.Best practice: Keep your sender name consistent across campaigns. Changing it often can confuse spam filters and your audience. A clear, recognizable sender name builds trust and improves open rates.
When someone subscribes to your email list and is added immediately, without a confirmation step. This is not a good practice, so most providers only allow double opt-in.
The percentage of subscribers who mark your newsletter as spam using the “Report Spam” button in their email client.This is one of the most important signals that spam filters use to decide whether your future emails land in the inbox or get blocked. Even a few complaints can hurt your domain reputation.Ideal range: Keep spam complaints below 0.1% (that’s fewer than 1 complaint per 1,000 emails). Anything higher is a red flag and can damage your deliverability.
A system used by email clients like Gmail or Outlook to automatically decide whether an email should go to the inbox or to the spam folder.Spam filters look at many signals, including your domain reputation, authentication (SPF, DKIM, DMARC), how often people open or click, and whether readers mark your messages as spam.For creators, the goal is to pass spam filters and land in the inbox so your subscribers actually see your content.
An automatic, one-to-one email triggered by an action (like a password reset or order confirmation). Unlike campaigns, these are functional, not promotional.
