Email deliverability checklist: 18 checks, five run for you
An email deliverability checklist covers everything mailbox providers judge before they accept mail: authentication, reputation, list hygiene, sending volume, content and unsubscribe handling. Enter your domain and this one runs the SPF, DKIM, DMARC, reverse DNS and domain blocklist checks inline, then lists the other 13 rules from Google, Yahoo and Microsoft to tick off, each with its source.
Runs SPF, DKIM, DMARC, reverse DNS and domain blocklist checks inline; tick the rest off by hand. DNS lookups only, nothing is sent. Free, no account.
0 of 18 done
Authentication
- Checked when you run your domain
Gmail and Yahoo require SPF from bulk senders, and Microsoft requires it to pass for domains sending over 5,000 messages a day to Outlook.com. Source
SPF checker → - Checked when you run your domain
Required by Gmail and Yahoo for bulk senders and by Microsoft for high-volume senders. The check tries common selectors; a custom one needs the DKIM checker. Source
DKIM checker → - Checked when you run your domain
Gmail, Yahoo and Microsoft require a DMARC record from bulk senders. Google says the policy can be set to none. Source
DMARC generator → Google requires the domain in the From header to match the SPF or DKIM domain for bulk mail. It shows on a delivered message, not in DNS. Source
Email header analyzer →- Checked when you run your domain
Google asks every sender, not only bulk senders, for valid forward and reverse DNS (PTR) on sending domains or IPs. Source
Reverse DNS lookup → Google asks all senders to use a TLS connection. Mainstream platforms do; a self-hosted server needs STARTTLS switched on. Source
Reputation
- Checked when you run your domain
Spam filters look up the domains in a message on lists such as URIBL. Check your sending IP separately on IP lists. Source
IP blacklist check → Google asks senders to keep the spam rate in Postmaster Tools below 0.10% and never reach 0.30%. Yahoo also names 0.3%. Source
Spam complaint rate calculator →
List hygiene
Google: don't purchase email addresses from other companies, and don't send to people who didn't sign up to get messages from you. Source
Microsoft lists list hygiene and bounce management among its recommendations: remove invalid addresses regularly. Verifying finds them before they bounce. Source
Email list health check →An address that hard bounced won't start working. Google advises cutting volume when messages start bouncing, then increasing slowly again. Source
Bounce message analyzer →Google suggests periodically confirming that recipients want to stay subscribed, and considering unsubscribing those who don't open or read your messages. Source
Sending volume
Google: start with a low volume to engaged users, send at a consistent rate, and avoid sudden spikes; immediately doubling volume can cause rate limits or reputation drops. Source
Email warmup calculator →Google treats close to 5,000 or more messages a day to personal Gmail accounts as bulk, permanently once reached; Microsoft's rules start above 5,000 a day to Outlook.com. Source
Bulk sender checker →
Content and headers
Google requires RFC 5322 formatting: one address in From, a valid Message-ID, and single-instance headers such as Subject and Date only once. Source
EML viewer →Google says subject lines, display names and headers must not mislead, such as Re: or Fwd: on messages that aren't replies. CAN-SPAM bans deceptive subject lines and headers in the US. Source
Spam words checker →
Unsubscribe
Gmail and Yahoo require RFC 8058 one-click unsubscribe headers on marketing and subscribed messages from bulk senders, plus a visible unsubscribe link in the body. Source
List-Unsubscribe header generator →Google and Yahoo ask bulk senders to process unsubscribes within two days. CAN-SPAM's own deadline is 10 business days, and it also requires a valid postal address. Source
Next step
Last item on the list: verify the list itself.
Records and reputation get mail accepted; addresses that don't exist turn into hard bounces that undo both. Check the whole list before the next send: $29.99 a month, never cut off.
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Sample result
acme.example has 3 of 18 items done: SPF and DMARC pass, the domain isn't listed, DKIM needs a look.
- Domain
- acme.example
- Live checks
- 5
- To tick off
- 13, each with its source
What this means for you
Fix DKIM first, then work down the 13 sending practices DNS can't show.
- SPF, DKIM, DMARC, reverse DNS and blocklists run live
- Google, Yahoo and Microsoft rules, each linked
- List hygiene, volume, content, unsubscribe
- Ends with the list itself: verify it
- Checklist
- Authentication
- Bulk senders
By SimpleVerifier Team · Last updated
How do I check my email deliverability?
- Enter the domain you send from, or any address at it, and press Run the checks.
- Read the five live results at the top of Authentication and Reputation: Pass, Check, Fail or Couldn't check. Anything marked Fail is also listed under "Fix first".
- Work down the rest of the list and tick each item you have covered. Each one names the rule, who sets it, and a link to the source.
- Use the tool link under any item you haven't covered, then finish with the last item: verify the list before the next send.
Example
- You enter
- The domain
acme.example, with SPF and DMARCp=nonepublished, no DKIM key on the common selectors, and no IPs named in SPF. - You get
- SPF and DMARC show Pass, DKIM shows Check with a pointer to the DKIM checker, reverse DNS shows Couldn't check (the sending IPs belong to the platform), and the domain blocklist row shows Pass if URIBL and the NordSpam DBL both answered. The other 13 items wait for your ticks; the counter reads 3 of 18 until you add them.
- Limits
- One domain a run, no account needed. Each live check allows ten runs a minute per IP address; DNS lookups only.
What should an email deliverability checklist include?
Six areas, because mailbox providers judge six different things. Authentication proves the mail is yours: SPF, DKIM and DMARC, aligned with the From domain, plus reverse DNS and TLS. Reputation is what your past mail earned: blocklist listings and the spam rate. List hygiene, sending volume, content and unsubscribe handling decide whether the next send keeps that reputation or spends it.
Every item here comes from a published rule rather than a rule of thumb: Google's email sender guidelines, Yahoo's sender best practices, Microsoft's requirements for high-volume senders, RFC 8058 and the FTC's CAN-SPAM guide. Where providers publish no number, such as a bounce rate, the checklist gives none.
Which checks does it run automatically?
Five, all DNS lookups on the domain you enter. SPF, DKIM (on the selectors common providers use), DMARC and reverse DNS for any IPs your SPF record names come from the same lookups as the bulk sender checker. The domain blocklist result comes from the domain blacklist check, which queries URIBL and the NordSpam DBL live.
The other 13 can't be seen from DNS. Alignment and TLS show on a delivered message, so the email header analyzer settles them. Spam rate is measured by the mailbox providers and shown in Google Postmaster Tools. List hygiene, volume, content and unsubscribe handling depend on how you send, so they are yours to tick off.
What are the Gmail and Yahoo bulk sender rules on this list?
Since February 2024, Google requires senders of more than 5,000 messages a day to Gmail accounts to set up SPF and DKIM, publish DMARC (p=none is enough), align the From domain with SPF or DKIM, support one-click unsubscribe on marketing and subscribed mail with a visible unsubscribe link, and keep the spam rate in Postmaster Tools below 0.3%. Yahoo's rules match, and both ask for unsubscribes to be processed within two days.
Some items apply to every sender, bulk or not: valid forward and reverse DNS, TLS, RFC 5322 formatting and SPF or DKIM. Microsoft added its own rule for domains sending over 5,000 messages a day to Outlook.com, Hotmail.com and Live.com: SPF and DKIM must pass and DMARC must be at least p=none. The Microsoft sender requirements checker covers it in depth.
Why does list hygiene sit on a deliverability checklist?
Because it is what the authentication records can't fix. A domain with perfect SPF, DKIM and DMARC still loses reputation when its mail goes to addresses that don't exist or to people who never asked for it. Google tells senders not to buy addresses and not to mail people who didn't sign up; Microsoft's recommendations include list hygiene and bounce management, in its words "remove invalid addresses regularly".
In practice that means three habits: verify addresses before mailing a list that is old, imported or bought in from a form you don't control; remove hard bounces after every send; and reconfirm or remove subscribers who stopped opening, as Google suggests. The email list health check finds duplicates, typos and dead domains free in your browser; finding mailboxes that no longer exist takes a verification run.
How often should I run through the checklist?
Run the live checks after any DNS change and before any send that is larger or different from usual: a new platform, a new domain or a list you haven't mailed in months. Adding a sending service often changes SPF and adds a DKIM selector, and that is when records break.
Go back over the manual items when results change: a rise in the spam rate in Postmaster Tools, a jump in bounces, or a drop in replies. The email domain health checker gives a score and fix list for the DNS side if you want one number to watch.
Is this the same as a deliverability test?
| This checklist | Deliverability test | |
|---|---|---|
| DNS checks | SPF, DKIM, DMARC, reverse DNS, domain blocklists | MX, SPF, DKIM, DMARC, blocklists |
| Rules DNS can't show | 13, each with its source | Not covered |
| Result | Items done out of 18, fix-first list | Pass or fail per record |
| Best for | Preparing a send or a new domain | A quick look at one domain's records |
The deliverability test and the email domain health checker go deeper on DNS; this page adds the sending practices around it.
Who uses this tool, and for what?
- Founders and marketers
- Go through it before a launch email or the first newsletter from a new platform, so authentication, unsubscribe headers and the list itself are covered before the send, not after the first complaints.
- Cold emailers
- Run each new sending domain, then work through list hygiene and volume: verified addresses and a slow ramp matter as much as the records for outreach domains.
- Agencies
- Use it as the onboarding audit for a new client: the live results show what DNS needs, and the manual items become the questions to ask about how they collect and mail their list.
- IT and email admins
- Confirm a DNS change kept SPF, DKIM, DMARC and reverse DNS passing, and point the marketing team at the unsubscribe and volume items they own.
What can’t this tool tell you?
- Five items are checked live; the other 13 depend on how you send and are only as accurate as your own ticks.
- DKIM is checked on common selectors. A custom selector needs the DKIM checker with that selector.
- It reads DNS and blocklists, not your sender reputation, spam rate or inbox placement; Google Postmaster Tools shows those.
- Ticks aren't saved. Reloading the page clears them.
- Rules change. Each item links to its source; check it if the date on this page is old.
Common questions
- What is an email deliverability checklist?
- A list of everything mailbox providers check before they put mail in the inbox: SPF, DKIM and DMARC authentication, reverse DNS, blocklists, spam rate, list hygiene, sending volume, content and unsubscribe handling. This one runs the DNS checks for your domain and links each other item to its source.
- How do I improve my email deliverability?
- Authenticate with SPF, DKIM and DMARC aligned to your From domain, only mail people who signed up, verify old or imported lists and remove hard bounces, increase volume slowly, add one-click unsubscribe and keep the spam rate below 0.1% in Google Postmaster Tools.
- What are the Google and Yahoo requirements for bulk senders?
- Senders of more than 5,000 messages a day to Gmail must set up SPF and DKIM, publish DMARC at p=none or stricter, align the From domain, support one-click unsubscribe on marketing mail, honour unsubscribes within two days and keep the spam rate below 0.3%. Yahoo's rules match.
- What is a good email spam rate?
- Google asks senders to keep the spam rate shown in Postmaster Tools below 0.10% and never reach 0.30%. Yahoo also names 0.3%. The rate is complaints divided by mail delivered to the inbox, measured by the provider, so you read it in their tools rather than your own.
- Does SPF, DKIM and DMARC guarantee inbox placement?
- No. They prove the mail is from you, which providers require, but placement then depends on reputation: spam complaints, bounces, engagement and how steadily you send. That's why list hygiene, volume and unsubscribe handling are on the checklist too.
- How long do I have to honour an unsubscribe request?
- Google and Yahoo ask bulk senders to process unsubscribes within two days. In the US, CAN-SPAM sets a legal deadline of 10 business days and also requires a valid physical postal address in commercial email.
Sources
Authentication and capacity are half of deliverability.
The other half is who you send to. Every hard bounce counts against the domain and inboxes you are sending from, and nothing in DNS can tell you which addresses on your list are dead.
- Bulk verification with real SMTP mailbox checks
- Hard bounces removed before a send, not discovered after
- Catch-all, disposable and role detection on every row
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