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Sent is not the same as delivered

Example · what the recipient checks
From
Sarah Miller <sarah@yourcompany.com>
To
purchasing@client.com
Subject
Maintenance quote 2027
  1. SPFpassed
  2. DKIMpassed
  3. DMARCpassed
  4. Delivered to Inbox

‘Your quote was in my spam folder.’ Not something you want to hear. Whether an email lands in the inbox is decided by the recipient, based on who you are, how you send and what you write. Here’s how to make your domain vouch for you.

Email hostingBy FINIC

The recipient decides, not you

When you click Send, the receiving mail server starts a quick assessment. Does this message really come from the domain shown at the top? Does this sender have a good reputation? Do people open and reply to their mail, or do they mark it as spam? And does the content look like what you would expect from a normal business email? There is no single trick that gets around the spam folder. It is the sum that counts. The good news: the most important parts are in your own hands, and they don’t need a marketing budget, just carefully configured settings and a few fixed habits.

Four questions, in a fraction of a second
01IdentityDoes this really come from this domain?
02ReputationHow has this sender behaved before?
03BehaviourDo recipients open this, or report spam?
04ContentDoes this look like normal business mail?

Make your domain vouch for you

Three settings in your domain’s DNS tell recipients that your mail really comes from you. SPF lists the servers allowed to send on behalf of your domain. DKIM adds a digital signature to every message, so it can be verified that nothing was changed on the way. DMARC tells a recipient what to do when those checks fail, and sends you reports on who is mailing on behalf of your domain. A common mistake: your website’s contact form, your invoicing package or your newsletter service also sends as your domain, but isn’t included in your SPF record. A domain also has only one SPF record. Start DMARC with p=none, read the reports and then tighten it.

Three checks, explained without jargon
SPFThe guest listWhich servers may send mail for your domain? If the sender isn’t on the list, the recipient becomes suspicious.
DKIMThe seal on the envelopeEvery message gets a digital signature. That shows the recipient nobody opened or changed it on the way.
DMARCThe instructions for the doormanWhat should the recipient do if SPF or DKIM doesn’t match: let it in, quarantine it or reject it? And send me a report.

You set up all three once for your domain. Your email provider gives you the right details.

Write like a person, not a brochure

Content weighs less than reputation, but it can tip the balance. Use a clear subject line without capitals or rows of exclamation marks. Link to your own domain instead of through link shorteners, and don’t send a message that consists of a single large image. A PDF attachment is fine; zip files, attachments with macros and executable files are often blocked. Always use the same sender name and a recognisable signature. And ask new contacts to save your address, or to mark your message as ‘not spam’ if it does end up in the wrong place: that helps that recipient’s filters learn.

Hands typing a message on a laptop at a wooden table

Keep newsletters and regular mail apart

A newsletter to hundreds of people behaves differently from a quote to one client. If some readers mark the newsletter as spam, you don’t want your quotes to suffer for it. So send bulk mail through a specialised mailing service and preferably from a subdomain, such as news.yourcompany.com. Only mail people who asked for it and remove addresses that no longer exist. The big providers are strict about this: since 2024 Gmail and Yahoo, and since 2025 Microsoft, require anyone sending thousands of messages a day to have SPF, DKIM and DMARC in order and to offer one-click unsubscribe.

Two senders, two reputations
Personal mail@yourcompany.comQuotesInvoicesAppointments Your own mailbox
Bulk mail@news.yourcompany.comNewsletterAnnouncementsOne-click unsubscribe A mailing service

If some newsletter readers complain, it affects the subdomain, not your quotes.

A new domain has to earn trust

A new domain or a new mail server has no history yet. Recipients are cautious. So start gently: first your regular correspondence with people who expect your message, and only later larger mailings. Build volumes gradually and watch what happens with bounces and replies. Never buy address lists; they often contain outdated addresses and so-called spam traps, which can damage your reputation in a single mailing. Moving to a different email provider? Plan the DNS changes in advance too, so that SPF and DKIM are right from day one.

Illustration · build up gently
Known contacts
Ongoing conversations
Small groups
Larger mailings

No fixed numbers: after each step, check bounces and replies before you go further.

Measure instead of hoping

Send a test message to a checking service or to your own Gmail and Outlook addresses and look at the message header. It shows for each check whether SPF, DKIM and DMARC passed. Read the DMARC reports, or let a service summarise them for you: they show which systems are mailing on behalf of your domain. If you send a lot to Gmail, Google Postmaster Tools gives insight into your reputation. Suddenly getting a lot of mail bounced? Check whether your server is on a blocklist. Make it a routine: every time you start using a new package that mails on your behalf, run through this list again.

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