Before sending emails, you need to make sure whether they can be delivered at all. With Mailtrap, you can check two important aspects: spam score and blacklisting.
Go to the Spam Analysis tab to view the Spam Report. It contains the general score and a detailed table with spam test points and their descriptions.
Mailtrap uses Apache SpamAssassin, the most popular email filter. It runs numerous tests on email headers and body text and assigns a score to each of them.
A score below 5 points is considered good. If your email gets more than 5 points, it will most likely be treated as spam by various email clients. In this case, check the rules that gained the highest score and fix your email template accordingly.
You will find the Blacklists Report in the Spam Analysis tab as well.
Mailtrap checks whether your IP or domain has been listed on any of the commonly used blacklists. It shows resources that have been queried and your current status. If your domain or IP is blacklisted, click the resource name; it's hyperlinked to the blacklist website -- check their rules for delisting and follow their instructions.