Why Emails Go to Spam and How to Fix It

Why do emails go to spam?

Spam filters are designed to protect users from unwanted, suspicious or harmful messages. They check many signals before deciding whether an email should go to the inbox, spam folder or be rejected completely.

These checks include the sender address, sending server, domain reputation, DNS authentication, message content, links, attachments, sending volume and recipient behaviour. If too many signals look risky, the message may be filtered into spam.

This can happen even when your email is genuine. A business may send a real quote or invoice, but if authentication is missing or the message looks suspicious, the receiving system may treat it cautiously.

1. Missing SPF records

SPF stands for Sender Policy Framework. It is a DNS record that lists which servers are allowed to send email for your domain. If SPF is missing or incorrect, receiving mail systems may be less confident that your message is genuine.

For example, if your domain sends email through your email hosting provider, your SPF record should include that provider’s authorised sending servers. If your website form sends email through a different service, that service may also need to be included.

SPF problems are common after moving email providers, changing website hosts or adding marketing tools. You can use DNS Lookup to check whether your domain has an SPF record.

2. Missing DKIM signing

DKIM stands for DomainKeys Identified Mail. It adds a digital signature to outgoing emails. Receiving mail systems can check that signature to confirm the message was authorised by the domain and was not altered in transit.

DKIM is especially important for business email because it gives receiving servers another reason to trust your messages. Without DKIM, your mail may still deliver, but it can be more vulnerable to spam filtering.

Most modern email hosting services provide DKIM settings or a DNS record to add. If your email provider supports DKIM, it is usually worth enabling it.

3. No DMARC policy

DMARC works with SPF and DKIM. It tells receiving mail systems what to do when messages fail authentication checks. It can also provide reporting so domain owners can see how their domain is being used.

A domain without DMARC may still send email, but it has less control over how failed authentication is handled. Adding DMARC helps strengthen your email setup and can reduce domain spoofing risk.

If you are new to DMARC, start carefully. Many businesses begin with a monitoring policy, then move to stricter policies once they are confident legitimate mail is passing SPF and DKIM.

4. Sending from the wrong mail server

A common reason emails go to spam is that the message is sent from a server that is not authorised for the domain. This often happens with website contact forms, WordPress websites or third-party systems.

For example, your business email may be hosted with one provider, but your website form may send messages directly from the web hosting server. If that server is not included in SPF or does not use proper SMTP authentication, messages may look less trustworthy.

The best fix is usually to send website mail through authenticated SMTP using your email provider or a trusted mail sending service. This helps ensure the message comes from an authorised source.

5. Poor sender reputation

Sender reputation is how much trust receiving mail systems have in your domain, mail server or sending behaviour. A good reputation improves the chance of inbox delivery. A poor reputation can lead to spam filtering or rejected messages.

Reputation can be affected by spam complaints, high bounce rates, sending to old or invalid addresses, sudden large sending volumes, compromised mailboxes or sending unwanted messages.

New domains may also need time to build reputation. If you have just registered a domain and immediately send lots of emails, some receiving systems may be cautious.

6. Your domain is new

New domains have little sending history. That does not mean they are bad, but receiving mail systems may not fully trust them yet. This is one reason new business email addresses should be used carefully at first.

Build reputation gradually. Start by sending normal business emails to real contacts who expect to hear from you. Avoid sending large campaigns from a brand-new domain before authentication is fully configured.

If you are launching a new business, set up your domain-based email early and use it consistently. Our Domain Services and Business Email Hosting pages can help you start with a cleaner setup.

7. Spammy wording or formatting

Message content can affect spam filtering. Emails with aggressive sales wording, excessive punctuation, misleading subject lines, too many links, all-capital text or strange formatting may look suspicious.

This is especially important for marketing messages, cold outreach, promotional emails and automated website messages. A normal business reply is less likely to trigger content filters, but it still needs to look clean and legitimate.

Avoid trying to trick filters. Write clear, honest subject lines. Use normal wording. Keep the message useful and relevant to the recipient.

8. Suspicious links or attachments

Links and attachments are common spam triggers. Emails with lots of links, mismatched link text, shortened URLs or suspicious domains may be filtered more aggressively.

Attachments can also cause problems, especially executable files, compressed files or very large attachments. Even normal PDFs can sometimes increase caution if the rest of the message looks suspicious.

For important business messages, keep attachments relevant and avoid sending unnecessary large files. If you need to share large documents, consider using a trusted file-sharing method instead of attaching huge files to every email.

9. Sending too many emails too quickly

Sudden high sending volume can look suspicious, especially from a new domain or new mailbox. This can happen when a business starts sending newsletters, bulk updates or promotional emails without warming up the domain properly.

If you send marketing emails, use proper permission-based lists and a suitable email marketing platform. Do not send large promotional campaigns from a normal business mailbox unless your provider supports that use.

For everyday business email, keep sending natural and expected. Quotes, invoices, support replies and customer messages should be fine when authentication and content are clean.

10. High bounce rates or old contact lists

A bounce happens when an email cannot be delivered. High bounce rates can damage sender reputation because they suggest a sender may be using poor-quality, old or purchased contact lists.

If you send newsletters or announcements, keep your list clean. Remove invalid addresses, avoid purchased lists and make sure recipients have a real reason to expect your emails.

For normal business email, check spellings carefully when sending to customers. A simple typo in an address can cause a bounce.

11. Recipients mark your emails as spam

Spam complaints are a strong negative signal. If recipients mark your emails as spam, receiving systems may become less likely to trust future messages.

This is most common with marketing or bulk email. People may mark emails as spam if they do not recognise the sender, did not expect the message, cannot unsubscribe easily, or receive too many messages.

Only send marketing emails to people who have agreed to receive them. Make the sender name recognisable and include a clear way to opt out where required.

12. Website contact form emails look fake

Website forms are a frequent source of spam-folder problems. A contact form may try to send an email “from” the customer’s address, even though the message is actually sent by your website server. This can fail authentication checks.

A better setup is usually to send form notifications from an address on your own domain, such as forms@yourbusiness.co.uk, and set the customer’s email as the reply-to address. This makes the message more technically accurate while still allowing you to reply to the customer.

If your website uses WordPress, a good SMTP plugin and properly authenticated mailbox can often improve form delivery.

13. Your mailbox or website may be compromised

If a mailbox or website is compromised, it may send spam without you realising. This can quickly damage reputation and cause legitimate emails to land in spam.

Warning signs include unusual sent messages, password reset emails you did not request, high sending volume, bounced spam messages, unfamiliar admin users or security alerts.

If you suspect compromise, change passwords immediately, check devices, remove unknown users, scan the website, update software and review mail logs where available.

14. Blacklists and blocklists

Some mail servers and IP addresses can appear on blocklists if they are associated with spam or suspicious activity. If your sending server is listed, emails may be rejected or sent to spam.

This is more common with shared or poorly managed mail servers, compromised accounts or bulk sending issues. A reputable email hosting provider helps reduce this risk, but no provider can prevent every problem if accounts are abused.

If you suspect a blocklist issue, check your mail server reputation and contact your email provider for help. Avoid repeatedly sending test emails without fixing the underlying cause.

How to fix emails going to spam

Fixing spam-folder problems usually means improving trust signals. Start with technical authentication, then review message content, sending behaviour and reputation.

Do not change everything randomly. Work through the basics in order: DNS records, sending method, content, reputation and testing. This makes it easier to see what improves delivery.

Check your DNS records first

DNS records are one of the first things to check when emails go to spam. If SPF, DKIM or DMARC are missing or wrong, receiving mail systems may be less likely to trust your messages.

Use DNS Lookup to check your domain’s records. If you have recently made changes, use DNS Propagation Checker to see whether updates have appeared across different networks.

Be careful when editing DNS. Incorrect records can affect email delivery. If you are moving email providers, make a copy of existing records before changing anything.

Use professional domain-based email

A professional email setup gives your business a better foundation than sending from a free personal account or an incorrectly configured website server. Domain-based email also allows proper DNS authentication.

If you want addresses such as hello@yourbusiness.co.uk, sales@yourbusiness.co.uk or support@yourbusiness.co.uk, start with Business Email Hosting. If you need a domain first, visit our Domain Services.

Once your mailbox is created, connect it using proper IMAP and SMTP settings. SMTP is especially important for sending because it authenticates outgoing messages.

Test before blaming the whole email system

If one message goes to spam, it does not always mean your entire email setup is broken. The issue may be a specific recipient, message, attachment, link or sending app.

Test carefully. Send a simple plain-text message to a few trusted addresses. Then test a normal business message. Then test the message that caused the issue. Compare the results.

If simple messages deliver but a specific message goes to spam, content or links may be the issue. If all messages go to spam, authentication or reputation may be more likely.

Small business example: quote emails going to spam

A local trades business sends quotes from quotes@businessname.co.uk, but customers keep saying they cannot find them. The first checks should be SPF, DKIM and DMARC, followed by the content of the quote email.

If the email contains several links, a large PDF attachment and sales-heavy wording, simplifying the message may help. The business should also check whether the quote system sends mail through authenticated SMTP.

Small business example: website form notifications going to spam

A website contact form sends enquiry notifications, but they land in spam. The form is sending directly from the website server and pretending to be from the customer’s email address.

A better setup is to send the notification from a domain-based address, such as forms@businessname.co.uk, through authenticated SMTP. The customer’s email should be placed in the reply-to field.

Small business example: new domain sending too much too soon

A new business registers a domain and immediately sends a large promotional campaign. Because the domain has little sending history, some providers treat the messages cautiously.

The better approach is to set up authentication first, send normal business messages gradually, and use a proper email marketing platform for bulk campaigns.

Common mistakes to avoid

One common mistake is only checking the message content and ignoring DNS. If SPF, DKIM and DMARC are missing, even a well-written email may struggle.

Another mistake is sending website form mail without SMTP authentication. This can make genuine enquiry notifications look suspicious.

It is also a mistake to keep sending the same failed message repeatedly without changing anything. If a message is being filtered, repeated sending can make the situation worse.

• Do not ignore SPF, DKIM and DMARC records.
• Do not send website form emails from unauthenticated server mail.
• Do not use misleading subject lines.
• Do not send large attachments unnecessarily.
• Do not send bulk campaigns from a normal business mailbox.
• Do not use old or purchased mailing lists.
• Do not ignore signs of a compromised mailbox or website.

FAQs about emails going to spam

Final thoughts

Emails go to spam when receiving mail systems do not fully trust the sender, domain, server, content or sending behaviour. The good news is that many spam-folder problems can be improved with the right checks.

Start with the technical basics: SPF, DKIM, DMARC, MX records and authenticated SMTP. Then review message content, links, attachments, sending volume and reputation.

For businesses, reliable email delivery is essential. Quotes, invoices, booking messages, support replies and contact form notifications all need to reach customers, so it is worth setting up your domain-based email properly from the start.