Email Deliverability Checklist: How to Reach the Inbox

Deliverability is whether your emails actually reach the inbox rather than the spam folder or nowhere at all. It is not a single setting you switch on. It is the combined result of technical setup, the quality of your list, what you send, and how consistently you send it. The good news is that most of it is within your control, and the checklist below covers the parts that matter most for small and mid-sized senders.

1. Send from your own domain

Before anything technical, check your sender address. Using a free webmail address such as name@gmail.com or name@yahoo.com as the “from” address for bulk email is a common mistake. You do not control those domains, so you cannot set up authentication for them, and receiving providers have every reason to be suspicious of bulk mail that claims to come from them.

Use an address on a domain you own, such as hello@yourbusiness.com. If you do not have a domain yet, buying one is the first deliverability investment to make. If you are setting up a new account, our getting started with MailerLite guide shows where account setup fits into this process.

Checklist

• Sender address is on a domain you own
• Sender name is recognizable (your name, your brand, or both)
• Reply-to address is a monitored inbox, not a black hole

2. Authenticate your domain: SPF, DKIM and DMARC

Authentication lets receiving servers confirm that an email claiming to be from your domain really was sent with your permission. There are three standards, and they work together. Your email platform will give you the exact DNS records to add; you paste them into your domain registrar or DNS host.

• SPF

  A list, published in your DNS, of the servers allowed to send email for your domain. Like a guest list at the door.

• DKIM

  A digital signature added to each email, which the receiver checks against a public key in your DNS. Like a tamper-evident seal.

• DMARC

  A policy telling receivers what to do if SPF or DKIM checks fail, and where to send reports. Like instructions for the doorman.

SPF in plain terms

SPF (Sender Policy Framework) is a DNS record listing which services may send email using your domain. If you use several services (your regular mailbox, your email marketing platform, an invoicing tool), they generally all need to be covered. You should have one SPF record per domain, not several.

DKIM in plain terms

DKIM (DomainKeys Identified Mail) adds an encrypted signature to every email. The receiver looks up your public key in DNS and checks that the signature matches. If the message was altered in transit or sent by someone without your key, the check fails. Your email platform generates the keys; you only publish the DNS record it gives you.

DMARC in plain terms

DMARC (Domain-based Message Authentication, Reporting and Conformance) builds on SPF and DKIM. It checks that the domain in your visible “from” address lines up with the authenticated domain, and tells receivers what to do when it does not: nothing (p=none), send to spam (p=quarantine), or reject (p=reject). Many senders start with p=none to collect reports and tighten the policy later once they are confident everything legitimate passes.

Checklist

• SPF record published and includes your email platform
• DKIM record published and verified by your platform
• DMARC record published (start with a monitoring policy if unsure)
• Test email shows PASS for all three

3. Meet the Gmail and Yahoo sender requirements

In 2024, Google and Yahoo began enforcing stricter requirements for bulk senders. Because Gmail and Yahoo addresses make up a large share of most consumer lists, these rules effectively set the baseline for everyone.

In practice, that means:

• Authentication as described above, with your “from” domain aligned to DMARC.
• One-click unsubscribe. Marketing emails should include the technical unsubscribe header that lets Gmail and Yahoo show their own “Unsubscribe” link, plus a clearly visible unsubscribe link in the email body. Reputable email platforms handle the header for you; your job is to not hide the body link.
• Process unsubscribes promptly. Remove people as soon as they ask. Your email platform normally does this for you automatically.
• Low spam complaint rates. Stay well under 0.3%. If you send to Gmail in volume, set up Google Postmaster Tools to see your rate.

Checklist

• Platform supports one-click unsubscribe headers (confirm in its docs)
• Visible unsubscribe link in every marketing email
• Spam rate monitored and kept well below 0.3%

4. Collect consent properly

Most deliverability problems start at the signup form. People who did not knowingly ask for your email are the ones who mark it as spam.

• Only email people who opted in. Never buy, rent or scrape lists.
• Be clear at signup about what you will send and how often.
• Consider double opt-in (a confirmation email before someone is added). It reduces typos, fake addresses and bot signups, at the cost of some confirmed signups.
• Protect forms from bots with the CAPTCHA or spam protection your platform offers.
• Keep records of consent. Depending on where you and your subscribers are located, privacy laws may require this.

For list-building methods that bring in engaged subscribers, see how to build an email list.

5. Keep your list clean

Sending to addresses that bounce or never engage tells mailbox providers your mail is not wanted.

• Remove hard bounces immediately (most platforms do this automatically).
• Review repeated soft bounces and remove persistent ones.
• Define “inactive” using clicks, purchases or site activity over a sensible window, since opens are unreliable after Apple Mail Privacy Protection. Our email marketing metrics guide explains why.
• Send a re-engagement email to inactive subscribers, then suppress those who do not respond.
• Never re-import old contacts who previously unsubscribed or bounced.

6. Write email people want to receive

Content alone rarely sends a well-authenticated email from a good sender to spam, but it does shape engagement and complaints.

• Make the sender and subject line instantly recognizable.
• Do not mislead in subject lines; it drives complaints.
• Keep a sensible balance of text and images, and add alt text.
• Use your own domain in links, or at least avoid link shorteners, which are often associated with spam.
• Include your physical mailing address where required by law.
• Send a plain, useful email over a heavily designed but empty one.

7. Send consistently

Mailbox providers like predictable patterns. A sender who mails twice a month at a similar volume looks more trustworthy than one who is silent for six months and then sends to the entire list at once.

• Pick a realistic schedule and stick to it.
• Avoid sudden large volume spikes; spread big sends if needed.
• If you have not emailed a list for a long time, start with your most recently engaged subscribers.

8. Warm up new domains and big lists

A new sending domain has no reputation yet. Rather than sending to your whole list on day one, start with your most engaged subscribers and increase volume gradually over a few weeks, watching bounces and complaints as you go.

Hypothetical example: a business moving 20,000 subscribers to a new platform and a new domain might send the first campaign to the few thousand people who clicked recently, then add more segments with each send, rather than mailing everyone at once. Your platform’s documentation may have specific warming advice; follow it where it exists.

The full checklist

• Sender address on your own domain, not a free webmail address
• SPF, DKIM and DMARC set up and passing
• One-click unsubscribe supported and a visible unsubscribe link in the body
• Spam complaint rate monitored and well below Google’s 0.3% threshold
• Only opted-in contacts; clear expectations at signup
• Bot protection on forms; double opt-in considered
• Hard bounces removed; inactive subscribers handled
• Honest subject lines and useful content
• Consistent sending schedule without sudden spikes
• Gradual warm-up for new domains or large migrations

If you are comparing platforms partly on deliverability support, our guide on how to choose email marketing software covers what to look for. No platform can fix a bad list, but a good one makes authentication and unsubscribe handling straightforward.