Step by step: ask whoever manages your domain to set up SPF, DKIM and DMARC; write only to people who expect your email; remove addresses that bounce; avoid sending a sudden large batch from a new mailbox; and ask a colleague with a different provider to tell you where your test email arrived.
In HawkOpen you can see per message whether the provider accepted, rejected or bounced it. On the Business plan, the Deliverability Guardian adds an assessment of bounce and rejection rates and pauses bulk sending when they are too high. It does not test spam folders or authentication records.