Increase our domain reputation, SPF settings, Gmail error

Job ID: 31332465

Budget: $10 – $30 USD

We need to set up and configure SPF and DMARC to prevent Goggle from blocking emails to our clients/students.
Our emails to Gmail mailboxes are being rejected with this error msg:

"""""""""""
Our system has detected that this
550-5.7.1 message is likely suspicious due to the very low reputation of the
550-5.7.1 sending domain. To best protect our users from spam, the message has
550-5.7.1 been blocked.
""""""""""""
Related categories: System Admin Bulk Marketing DNS Email Handling