Configure spf and dkim
I will configure and validate your server's spf ,dkim for better Email deliverability.
SPF (Sender Policy Framework) is a DNS text entry which shows a list of servers that should be considered allowed to send mail for a specific domain.
DKIM (DomainKeys Identified Mail) should be instead considered a method to verify that the messages' content are trustworthy, meaning that they weren't changed from the moment the message left the initial mail server.
DMARC (Domain-based Message Authentication, Reporting and Conformance) empowers SPF and DKIM by stating a clear policy which should be used about both the aforementioned tools and allows to set an address which can be used to send reports about the mail messages statistics gathered.