Why my messages go to yahoo/hotmail/gmail junk/bulk/spam folder?
Usually, this issue is caused by spam-fighting filters on the remote server, incorrectly flagging your messages. Remote email servers have different types of SPAM protection rules for detecting which email is SPAM and which is not.
What you can do is to activate SPF and DKIM records for your domain name.
This can be done from your Site Tools > Email > Authentication.
The SPF record ensures that remote mail servers that do SPF checks will accept email messages from your domain only from the server which you currently use. DKIM also proves the legitimacy of the email sender.
Both records are important for fighting SPAM and email forgery. You can read more about SPF and DKIM records in our articles below:
How to enable SPF for my domain?
The last thing you can do to resolve the problem is to ask your recipients to add your email in their address books. Most of the time this action helps and resolves the problem.