How to Improve Business Email Deliverability

Quick answer: To know how to improve business email deliverability, the top priority is to correctly configure four DNS records on your domain: MX, SPF, DKIM, and DMARC. This authentication proves to receiving servers that your message is legitimate and authorized by your business, preventing your emails from landing in spam or being outright blocked.

What is email deliverability and why does it affect your sales?

Email deliverability is the actual ability of a message to reach the recipient's primary inbox, rather than being diverted to the spam folder, trash, or rejected by the destination server. There is a fundamental difference between delivery and deliverability: a message can technically be delivered by the server, but if it ends up in the trash folder, the recipient will never see it.

For small business owners and managers, a low deliverability rate means direct financial loss. Business proposals sent to potential clients go unanswered, invoices and payment links are never opened, and support communications create client frustration. When a lead requests a quote and cannot find it, the immediate assumption is often that your company was inattentive or disorganized.

Major email providers have made their receiving rules substantially stricter in recent years. According to Google's email sender guidelines, messages sent without proper domain authentication are much more likely to be classified as spam or rejected automatically to protect users against fraud and phishing.

Which DNS records define your business domain's reputation?

Your business email reputation does not depend solely on the copy you write, but above all on the technical architecture configured in your domain's DNS (Domain Name System) zone. There are four essential records that every professional email setup needs working in perfect sync:

1. MX (Mail Exchange) record

The MX record tells the internet which servers are responsible for receiving messages on behalf of your domain. Without it, no one can send emails to your team. Although MX handles receiving, conflicting or misconfigured MX records cause resolution errors that harm the entire operation. You can check the details of this setup in our article on the MX record and how to configure it on your domain.

2. SPF (Sender Policy Framework) record

SPF is a TXT record in your DNS that defines a public list of IP addresses or servers authorized to send emails on behalf of your domain. According to the formal specification of RFC 7208, when a destination server receives a message from your business address, it checks the list in your SPF; if the sending server is not on the list, the message is treated with immediate suspicion.

3. DKIM (DomainKeys Identified Mail) record

DKIM adds an invisible cryptographic signature to the header of every message your business sends. According to the technical standard RFC 6376, the receiving provider uses the public key published in your domain's DNS to validate this signature. This process ensures that the email genuinely originated from your business and that no intermediary altered its content in transit.

4. DMARC (Domain-based Message Authentication) record

DMARC unifies SPF and DKIM, telling destination servers what to do if a message fails these checks (do nothing, quarantine, or reject). As detailed in RFC 7489, DMARC also allows you to receive reports on who is attempting to use your domain across the internet. If you have not yet implemented this policy, it is worth reading our guide on what DMARC is and how to configure it.

What DNS errors most often send business email to spam?

Many businesses hire an email service and assume the technical work is done. However, small oversights in the domain control panel destroy deliverability. Below are the most common issues on small business domains:

• Multiple SPF records in the same DNS zone: A domain can only have a single TXT-type SPF record (v=spf1 ...). Creating two separate SPF records invalidates the check under RFC 7208 and causes strict servers to drop the message.
• Missing or truncated DKIM key: Because signature keys are long alphanumeric strings, people often copy the code with extra spaces or cut off the end, breaking cryptographic validation.
• Technical DNS limitation at your domain registrar: Anyone who registered a .com.br domain directly through their domain registrar frequently faces a technical obstacle. The free DNS service provided by the registry itself does not allow the use of the underscore character (_) in record names, as stated in the technical specifications of Registro.br. This prevents direct creation of the DKIM record (which typically uses keys like default._domainkey) and verification records. The correct, recommended way to bypass this restriction is to migrate domain DNS management to Cloudflare (on its free plan), updating the DNS servers in your domain registrar's panel and adding the email records in Cloudflare.
• New domain without a warm-up period: Sending dozens of sales emails on the first day of a corporate domain's existence triggers automated spam filters. Volume must grow organically and legitimately.

To make sure your address does not suffer from these pitfalls, check out our practical guide on how to verify if your domain is configured for email.

DNS Record	Type	Main Function	Impact if Missing or Incorrect
MX	MX	Indicates who receives messages	The company receives no external emails
SPF	TXT	Lists authorized senders	Messages land in trash or fail delivery
DKIM	TXT	Digitally signs content	Providers distrust email integrity
DMARC	TXT	Defines action for SPF/DKIM failures	Domain vulnerable to spoofing and lower delivery score

How does Domailo simplify DNS configuration for your team?

Configuring DNS parameters manually in complex panels can be intimidating for anyone who just needs to focus on sales and customer support. At Domailo, the setup was designed specifically to simplify this workflow for small and medium-sized businesses.

Domailo provides professional email using your company's own domain and a modern, fast webmail interface directly in the browser, supporting light and dark modes. Unlike traditional competitors that charge high fees per individual user—disproportionately driving up costs as the company grows—Domailo uses a flat-rate pricing model per organization. This means budget predictability for your business:

• Startup plan: US$ 5.00 per month (or US$ 50.00 per year with upfront payment, with 10 monthly payments covering 12 months). It offers 2 users, 2 mailboxes, and 1 domain.
• Essential plan: US$ 9.00 per month (or US$ 90.00 per year). It offers 5 users, 5 mailboxes, and 3 domains.
• Team plan: US$ 19.00 per month (or US$ 190.00 per year). It offers 20 users, 20 mailboxes, and up to 10 domains.

All paid plans include the same essential features, differing only in user, mailbox, and domain capacities. You connect a domain you already own and immediately receive the exact DNS records (MX, SPF, and DKIM) ready to copy and paste into your DNS provider.

With Domailo, you also easily solve shared inbox management. The system lets you link multiple people to the same mailbox (such as contato@suaempresa.com or vendas@suaempresa.com). Each team member accesses the account with their own individual login, eliminating the risky need to share master passwords. In addition, administrators get a unified view of all company mailboxes.

It is important to stay transparent: Domailo does not include domain registration or renewal (you connect a domain purchased from your domain registrar or another registrar), does not offer access via legacy protocols like IMAP or POP for local client synchronization (access is exclusively through modern browser webmail), and does not perform automated migrations of old message history. For those needing a complete office suite with integrated spreadsheets or desktop apps, tools like Microsoft 365 or Google Workspace may make sense. But for small businesses that want reliable business email, high deliverability, ease of use, and fair pricing, Domailo is the right choice.

How to improve business email deliverability: step-by-step domain setup

If you want to solve your company's deliverability issues once and for all, follow this four-step roadmap:

1. Connect the domain to your email provider: In Domailo, you enter your domain name in the admin panel and immediately see the table with the MX, SPF, and DKIM records generated for your account.
2. Access your DNS manager: If your domain is a .com.br managed on your domain registrar's DNS, transfer DNS authority to Cloudflare (free plan) by changing the nameservers. If you are with another provider that supports special characters like underscores, access that provider's DNS zone.
3. Create the specified records: Carefully copy the MX record values with their respective priority, add the TXT record for SPF, and publish the TXT record for the DKIM public key.
4. Send a test email and validate headers: After DNS propagation, send an email from your webmail to an external test account (such as a personal Gmail account). When opening the received message, click "Show original" and confirm that the SPF, DKIM, and DMARC fields show a "PASS" status.

Why choose Domailo to protect your business communication?

Your brand's reputation depends on messages arriving on time without getting lost in trash mail. Continuing to use free accounts ending in generic providers (@gmail or @outlook) conveys an amateur image to clients, while traditional services charge per-user monthly fees for simple corporate features.

Domailo balances professionalism, top-tier deliverability, and administrative ease at a price that fits any small business budget. You get a 30-day free trial on paid plans to verify everything in practice. A credit card is only added after you verify domain ownership, and billing only begins at the end of the trial period if you choose to keep the service. If you cancel, your data is not deleted, and the account remains accessible in read-only mode.

Create your Domailo account, configure your DNS records in just a few minutes, and ensure your business emails always land where they belong: in your clients' inbox.