Deliverability problems are almost always a missing or misconfigured DNS record, not a "reputation" problem you can't fix. Check these in order.

1. SPF

Your SPF record lists which servers are allowed to send mail for your domain. Missing or incomplete SPF is the single most common cause of mail landing in spam.

2. DKIM

DKIM signs outgoing mail cryptographically so receiving servers can verify it wasn't altered or spoofed in transit. Most mailbox providers, including ours, generate this automatically — you just need to publish the DNS record.

3. DMARC

DMARC tells receiving servers what to do when SPF or DKIM checks fail, and gives you a way to see who's sending mail claiming to be from your domain.

4. Consistent sending domain

Sending marketing email from a domain that also handles your transactional/support email can hurt both if one gets flagged. Consider a subdomain split for high-volume sending.

Quick check: Run your domain through a free SPF/DKIM/DMARC checker tool — most deliverability issues show up immediately as a missing record.

Once all three records are in place and consistent, deliverability issues are usually resolved within a few days as mailbox providers re-evaluate your domain's reputation.