If your email lands in the spam or junk folder, the cause can be your test habits, the content of the email or your sender reputation. This article helps you find out which.
Check your test sends first
If only your own tests go to spam, the problem may be the tests themselves:
- Your company's mail server may start filtering many tests from the same sender. Ask your IT department to add the Symplify sending IP addresses to their allowlist. Contact support if you don't know which IP addresses you send from.
- Gmail and Outlook.com learn from how you treat each sender. If you delete tests without opening them, or never load images, the filters learn that you don't want the email. Open your tests, and if one lands in spam, mark it as Not spam. Add your sender address to your contacts or safe senders list.
A test that goes to spam in your own inbox doesn't mean the email goes to spam for all your contacts at that provider.
Check the content
The most common content reasons for spam filtering are:
- Too many images and too little text. This is by far the most common trigger. Spam filters can't read images, and spammers often send email that is a single large image.
- A text version that doesn't match the HTML. Symplify always sends a plain-text version along with the HTML. Check that the text version has the same content, so spam filters don't see two different messages.
- A subject line in capital letters.
- Links that look misleading, such as URLs written out as link text, or public link shorteners. See Deliverability basics.
Don't try too hard to write around spam filters. Today's filters rely mostly on your reputation.
Check your reputation
If many contacts find your email in spam, the cause is usually your sender reputation:
- Only send to contacts who opted in. Gmail doesn't count bought lists or pre-checked sign-up boxes as opt-in. See Healthy lists and permission.
- Use the same sender address for the same type of email.
- Make sure your sender domain is authenticated.
- Look at your bounces and complaints, and check whether you are on a blocklist. See Blocklists and spam traps.
How Gmail and Outlook.com filter
Gmail filters based on patterns across messages and on what its users mark as spam. When you open an email in the Spam folder, Gmail shows a short explanation at the top of why it was placed there. Use it as a clue.
Outlook.com uses machine-learning filters (SmartScreen) that learn from how each user has treated email from a sender. The first time you send from a new sender name or address, Outlook.com may ask the recipient whether to trust the sender, or place the email in junk.