Email is filtered as spam
updated 10 days ago
You've just installed your brand new HTML email signature and sent your first email. But the recipient hasn't received it. Looking into the issue, you discover it's been caught up in a spam filter! It must be the email signature, right?
How do spam filters work?
Keep a healthy balance of text and images.
Image heavy emails without much text can raise a red flag in spam filters. Although different spam filters have other criteria for a healthy balance of text and graphics, it is recommended to maintain a proper text-to-image ratio to ensure your emails are delivered. Aim at 80:20 text to image ratio as a thumb-rule to be safe (60:40 text to image ratio can be sufficient).
Only use the link to web pages.
Having a URL path that leads to a PHP page will get your email filtered as spam with 100% certainty.
Keep the number of links below 6.
When you check the emails in your spam folder, you'll notice that they often include many links. Therefore, try and reduce the number of links in your email signature. Having 5 links usually is not a problem.
Keep a healthy balance of the skin and non-skin colors.
Most spam filters estimate the intensity of skin and non-skin color pixels in your emails. Mostly when you use head-shot photos, it's critical to test OK for a few pilot users. We've also seen emails with campaign banners getting filtered as spam because the banner skin color ratio was too high.
Create your own image path (URL).
Generally, we recommend using MySignature images to secure that they will not get your email spam filtered.
If you deal with a client that specifically white-listed your domain, then you could try and use the image path to your own server:
Avoid sending default mobile signatures.
Although the “Sent from iPhone” line as your signature most probably won’t be treated as SPAM by email filters, it can be viewed as such by the recipient. While some people ignore those disclaimers as a relic of the previous decade, others might view it as highly unprofessional and careless. If you care about your brand, the best idea is to unify your email signatures across various devices and email clients.
Test your email signature.
If you are not sure what is wrong with your email signature, the excellent idea is to test it thoroughly – add one element at a time, send test emails to various recipients and from different IPs, and so on. Sometimes, emails land in SPAM just because someone added you to their blacklist by mistake. It is widespread to do this on a mobile app. Surprisingly, doing so can also affect desktop email clients, even if the blacklist is not accessible from these desktop apps.