How to Reduce Your Emails Being Marked as Spam

Email spam filters are designed to protect people from unwanted or malicious emails. However, legitimate emails can sometimes be incorrectly flagged as spam.

By following the guidelines below, you can significantly reduce the chance of your messages being filtered into the recipient’s junk or spam folder.

Best Practices to Prevent Emails Going to Spam

1. Use a Clear and Relevant Subject Line

Spam filters analyse subject lines very closely.

Avoid:

• ALL CAPS SUBJECTS

• Excessive punctuation (!!!)

• Misleading or vague wording

Better examples

✔ Meeting Update – Friday 2pm
✔ Invoice #1234 – May Services
✔ Project Update – Website Migration

Clear, honest subject lines help email systems recognise legitimate communication.

2. Avoid Spam Trigger Words

Certain words are frequently used in spam campaigns and may increase filtering risk.

Examples include:

• FREE

• WINNER

• ACT NOW

• LIMITED TIME

• GUARANTEED

• CLICK HERE

Using these occasionally is fine, but multiple trigger words in one email can increase spam scoring.

3. Keep Formatting Clean and Professional

Emails that look overly promotional or poorly formatted may be flagged.

Recommended formatting

✔ Normal sentence case
✔ Simple paragraphs
✔ Minimal colours and fonts
✔ Avoid large blocks of text

Avoid emails that contain:

• Too many images

• Multiple font styles

• Large colourful text

• Excessive links

4. Do Not Send Large Attachments

Large attachments can increase spam filtering risk.

Best practice:

• Keep attachments under 10MB

• Use OneDrive, SharePoint, or cloud links for larger files

Example:

Instead of attaching a 50MB file, send a secure sharing link.

5. Send Emails Only to People Who Expect Them

Spam filters analyse recipient engagement.

Emails sent to people who:

• Do not recognise the sender

• Never reply

• Mark messages as spam

…can negatively affect future deliverability.

Always ensure the recipient expects the email.

6. Avoid Sending the Same Email to Large Groups

Sending the same message to many recipients can resemble spam behaviour.

Recommended alternatives:

✔ Use BCC for large lists
✔ Send emails in smaller groups
✔ Use a proper mailing platform for newsletters

7. Ask Recipients to Add You to Their Safe Senders List

If someone frequently misses your emails, ask them to add your email address to their contacts or safe sender list.

This tells their email system that your messages are trusted.

8. Avoid Too Many Links

Spam filters examine links carefully.

Best practice:

• Limit the number of links

• Ensure links go to legitimate websites

• Avoid shortened links (bit.ly etc.)

9. Maintain a Professional Email Signature

A proper email signature improves trust signals.

Include:

• Your name

• Business name

• Phone number

• Website

Example:

Nick Smith
HealthyPC Pty Ltd
support@healthypc.com.au
www.healthypc.com.au
08 XXXX XXXX

Try to avoid adding to many links to other sites within your signature

If Your Email Still Goes to Spam

If emails continue being marked as spam, the issue may be related to:

• Email domain reputation

• SPF / DKIM / DMARC configuration

• Server blacklisting

• Email hosting configuration

In these cases, please contact HealthyPC Support for further assistance.