How to Fix Personal Emails Going to Spam from a Custom Domain?

1. Verify Your Domain and IP Configuration

For a custom domain sending email messages, it is important to:

1.1. Publish an MX record in DNS.

An MX record is a type of DNS record that specifies the mail servers responsible for receiving email messages on behalf of a domain. Although an MX record is not technically involved in the sending process, it is highly recommended for a sending domain because some email servers may refuse a message for security reasons if the sending domain has no valid MX record.

1.2. Publish a valid A record.

An A record translates a hostname into an IP address. Email receiving servers may perform this check in order to verify the legitimacy of the sending domain. This is required when you set up your own mail server to send email messages.

1.3. Publish a valid PTR record.

Additionally, if you are operating your own mail server, you need to ensure that your mail server’s IP address has a valid reverse DNS (PTR) record. Receiving servers may check if the sending IP address correctly translates into a hostname and if the hostname’s A record is pointing back to the same IP.

2. Verify Email Authentication

Email authentication proves to receiving mail servers that your emails are legitimate and highly increases the potential of inbox placement. A missing or incorrect SPF, DKIM, or DMARC record is one of the most common reasons personal emails from custom domains end up in spam. Therefore, you’ll want to double check your sending domain has valid authentication records:

2.1. SPF (Sender Policy Framework).

An SPF TXT record specifies which mail servers can send emails on behalf of your domain. Ensure that the SPF record has a valid syntax and includes all legitimate email sources.

2.2. DKIM (DomainKeys Identified Mail).

DKIM digitally signs outgoing emails to verify they haven't been altered in transit. The sending server creates a cryptographic hash of the message, uses a DKIM private key to encrypt the hash, and adds it as a DKIM signature to an outgoing email.

The receiving server also creates the message hash using the same fields and uses a DKIM public key (published as a DNS TXT record) to encrypt the hash. If the two hashes match, the message is considered authentic and passes authentication by DKIM.

As each sender uses its own DKIM record with the unique selector, it is important to have a valid DKIM TXT record associated with each legitimate sender in the domain’s DNS.

2.3. DMARC (Domain-based Message Authentication, Reporting, and Conformance).

DMARC stands for the third layer of email authentication that tells receiving servers how to handle emails that fail SPF or DKIM checks. Using different DMARC policies, you can instruct email receivers to send failed emails to the Junk folder or block them altogether.

DMARC also allows senders to receive reports that provide insightful information about email sources, volume, SPF and DKIM domains, and email authentication outcomes. A valid DMARC record is a requirement for bulk senders; it is also highly recommended for any domain as it increases the credibility of the sender.

You can easily test your domain setup and authentication with this email security checker tool. Dmarkoff instantly performs an audit of your domain including the report about the SPF, DKIM, DMARC, MX, and TXT records.

3. Check Your Domain Alignment

Alignment matters for DMARC authentication. Email receiving servers look at how your domains used in the email’s From field, Return-Path, and DKIM signature are aligned. Your domain can have valid authentication records in DNS, but if the domains used in three places are not aligned, the email fails DMARC authentication.

In fact, a DMARC test can pass based on either SPF alignment or DKIM alignment alone. Therefore, for your custom domain used to send emails, it is necessary to configure either of these:

3.1. DKIM Alignment.

DKIM alignment matches the domain used in the email’s From header field to the domain used in the d= tag in the signature. In the strict mode, the domains must match exactly; in the relaxed mode, the organizational domains in both places must match. If the domains don’t match, a message fails the DKIM alignment test.

Examples:

From: support@company-name.com

DKIM domain: company-name.com (strict or relaxed mode), email.company-name.com (relaxed mode)

DKIM alignment: PASS

From: support@company-name.com

DKIM domain: gmail.com

DKIM alignment: FAIL

When you send emails from your custom domain, email service providers allow you to configure DKIM signing on behalf of your domain in order to be compliant with DKIM alignment and DMARC requirements.

3.2. SPF Alignment.

SPF alignment matches the domain used in the email’s From header field to the domain used in the Return-Path (Envelope From, Mail FROM, Bounce Email Address) field. In the strict mode, the domains must match exactly; in the relaxed mode, the organizational domains in both places must match. If the domains don’t match, a message fails the SPF alignment test.

Examples:

From: support@company-name.com

Return-Path: company-name.com (strict or relaxed mode), bounce.company-name.com (relaxed mode)

SPF alignment: PASS

From: support@company-name.com

Return-Path: gmail.com

SPF alignment: FAIL

The ability to set up a custom Return-Path domain depends on the email service provider. Some providers support this configuration, some don’t. It is advised that you contact your ESP for further information.

4. Check Your Sender Reputation

Even perfectly authenticated personal emails sent from your custom domain can be filtered out as spam if your domain has developed a poor reputation.

The factors that negatively affect sender reputation include:

• • Sending large volumes too quickly
• • High spam complaint rates
• • High bounce rates
• • Sending to purchased email lists
• • Sending to inactive users
• • A previously abused domain

The best practices for maintaining a good sender reputation are:

4.1. Track Email Metrics.

Email service providers collect a lot of valuable metrics that help senders understand how their emails perform. It is important to look at email open rates, click rates, and conversions to measure the effectiveness of your campaigns. The better your emails are engaged, the higher your sender reputation.

4.2. Maintain Quality Email List.

Your target audience determines the success or failure of your email campaigns. Maintaining a good list of recipients is crucial regardless of what type of emails you send. Therefore, it is important to avoid sending to:

• • Invalid addresses
• • Recipients who reported your previous emails as spam
• • Unsubscribed users
• • Inactive users

A small but active and engaged list can bring more benefit than thousands inactive users.

4.3. Check Your Domain and IP Blacklisted Status.

Blacklisted IPs and domains can cause delivery failures or Spam placements. You’ll want to check your custom domain and dedicated IP address against blacklists with monitoring tools like MXToolbox on a regular basis.

4.4. Show Consistency.

Inbox providers like to see consistency in volume and frequency. Sudden increases as well as long periods of inactivity work against your reputation. It is recommended to create sending patterns and follow them. If your list grows, your sending volume increases – this is a natural process. But avoid jumping from 100 emails a day to 10,000 at once.

4.5. Use Monitoring Tools.

Some inbox providers offer tools that analyze emails sent from a domain or IP and offer metrics reflecting the sender’s activity. These include:

• • Google Postmaster
• • Yahoo Sender Hub
• • Microsoft SNDS (for senders with dedicated IP addresses)

For instance, in Google Postmaster and Yahoo Sender Hub, you can check your user reported spam rate to see if you are compliant with the allowed threshold. If you send from a dedicated IP, the Microsoft SNDS report will show you spam trap hits and complaints. As these directly impact your reputation, it is recommended to check your domain metrics on a weekly basis.

5. Avoid Spam-Like Content

Even personal emails can trigger spam filters if they contain spam-like elements.

It is recommended that you avoid:

• • ALL CAPS subject lines
• • Excessive exclamation marks!!!!
• • Too many links
• • Large image-only emails
• • Large or suspicious attachments
• • Suspicious domains in URLs
• • Embedded videos

Keep messages conversational and natural. Only include links and images hosted on trusted domains. Add large attachments to a .zip file or upload them to a website and send the download link.

6. Ask Recipients to Mark Your Email as "Not Spam"

If trusted contacts consistently move your emails from Spam to Inbox or add your address to their contacts, mailbox providers learn that your messages are wanted. Not only do these actions help your personal emails land in the inboxes, they will increase your custom domain reputation in general.

7. Test Your Email Deliverability

Before sending important emails, consider testing them using deliverability tools like this spam tester. These tools can identify:

• • Email placement rates;
• • Spam score issues;
• • Blacklisted IPs;
• • Email content problems;
• • Broken authentication records.

Testing your deliverability in a regular manner is a recommended practice regardless of your email volume, frequency or reputation level. Email testing tools like GlockApps help you identify the problems early before they seriously impact your business, internal communications, and user experience with your brand.