The most common types of email security are spam filters, antivirus software, firewalls, and encryption. The first step in email security is to make sure that a recipient is a legitimate person. This can be done by using a DMARC policy which will tell the sender if they should deliver the email or not. The second step is to make sure that the sender is not a malicious person. This can be done by using an SPF policy which will tell the recipient if they should trust the sender or not. The third step in email security is to make sure that any attachments are safe for opening and this can be done by using an AV policy which will scan all attachments for viruses before opening them and lastly, making sure that your emails are encrypted with TLS so that no one else can read them while they are being sent over the internet.