Whether your emails are successfully delivered, or end up in a spam or junk folder may depend upon the content of your message. To avoid delivery issues or having your messages flagged as spam or junk, you might want to follow these guidelines.
Avoiding delivery issues
- Do not use one big image as your message. Image-only messages are routinely routed to spam or junk folders.
- Avoid inserting a large image in your message (e.g. 900 pixels wide), even if you manually reduce the display size of the image. Instead, optimize the size of the image using TinyPNG or any other image optimizer tool.
- Limit the ratio of images to text within your message. Ideally, you should have at least a 65% to 35% text to image ratio.
- Do not embed video because most email readers do not support it. If necessary, you can provide a link to the video.
- Do not embed forms in your message.
Avoiding spam or junk filters
- Encourage your members to add your email address to their safe senders list aka whitelist. For instructions on adding email addresses to whitelists on different email clients, click here.
- Take the time to compose a clear subject line that gets to the point without any hyperbole. Do not use exclamation marks or all capitals. You can, however, use a question mark.
- Within your message, avoid spam trigger words like "free", "cash", "prize", "viagra" etc.
- Limit the number of links in your message to 5 or fewer.
- Use an opt-in mechanism to avoid sending unwanted messages that might be reported as spam. For more information, see Providing an opt-in mechanism.
- Limit how often you send email blasts. The more often you send, the less likely your messages will be opened. A high percentage of unopened messages can be interpreted as a symptom of spam by your ISP.
- Before sending your message, test it using a spam testing tool such as Mail Tester.
- Monitor your open rates and click rates. If your rates are declining, you might want to review your subject lines and email frequency.
- If you're using a custom domain, authenticate your email address using SPF and DKIM. For more information, see Custom domain setup.