There is a possibility that when sending emails from your hosting account to Yahoo, Hotmail, Gmail, they are delivered as unwanted emails. Usually, this happens because of complex antispam filters remote server which mistakenly consider your emails as spam. Remote email servers have different types of protection rules in order to improve detecting which emails are spam and which ones aren’t. There is no definite solution for this. At Top.Host, SPF record is already installed on all our Linux servers.

What you can do is ask from your email receivers, to add your email address in their contacts. This often solves the problem, however, it’s hard to implement it. 

Alternatively, you can create and add an SPF record to your domain DNS through Plesk. This specific record ensures that remote mail servers with filters for SPF check, will always accept emails from your domain if you use the same server. The above procedure is considered very effective against unwanted emails and forgery.

You can add an SPF record through Plesk’s DNS Settings.

You can find more information about SPF record, here.