If customers keep finding your emails in spam, the cause is almost always your domain's email settings. Fix those first, then look at the other causes below.
| Cause | The fix in short |
|---|---|
| Domain not set up | Add SPF, switch on DKIM, add DMARC |
| A service sending as you isn't listed | Add it to SPF, or set up its DKIM signing |
| Bad reputation | Secure the mailbox, then ask to come off blacklists |
| The email looks like spam | Avoid image-only emails, short links and risky attachments |
| The customer's own filter | Ask them to mark you "not spam" |
Your domain isn't set up
Before a mail server accepts your email, it checks three settings on your domain. SPF lists the services allowed to send as you. DKIM signs each email so it can't be changed on the way. DMARC tells the receiving server what to do with email that fails.
If any are missing or wrong, Gmail and Outlook are far more likely to send your email to spam or reject it. Gmail requires every sender to have at least SPF or DKIM, and large senders must have all three.
To fix it, add or correct your SPF record, switch on DKIM in Google Workspace or Microsoft 365, and add a DMARC record.
A service sending as you isn't listed
Xero, MYOB, your website's contact form, booking systems and newsletter tools often send "from" your address. If one isn't in your SPF record or signed with DKIM, its emails fail even when your normal email is fine. That's why "my emails are fine, but my invoices go to spam" is so common. Each service's help pages explain what to add.
Your mailbox has a bad reputation
If your mailbox was hacked and used to send spam, servers may distrust everything from you for a while. Bounce-backs mentioning "blocked", "blacklisted" or "reputation" are the sign; see what bounce-back errors mean. Change the password, switch on two-factor sign-in, check for forwarding rules you didn't create, then ask to be removed from any blacklist.
The email itself, or one customer's filter
Filters also read the email. One big image, shortened links, lots of capitals, or .zip and macro attachments can tip a borderline email into spam. A normal quote with a PDF attached is fine.
If only one customer has the problem, it's probably their own filter. Ask them to mark your email "not spam" and add you to their contacts.
When to get help
If SPF, DKIM and DMARC are missing or failing, or you're not sure which services send as you, it's worth handing over. A wrong change can stop your email arriving at all. Start with our free website check, which checks these settings too.