The records, sending habits and mailbox issues behind many delivery problems.
Start with domain authentication
SPF, DKIM and DMARC help receiving mail systems confirm who is allowed to send from your domain. Missing or conflicting records often weaken delivery.
- Use one valid SPF record
- Enable DKIM for the active mail platform
- Start DMARC reporting before applying a strict policy
Check the sending pattern
A new mailbox that suddenly sends a large campaign looks risky. Build a normal sending history, remove old contacts and avoid sending the same message to people who did not ask for it.
Test before blaming the recipient
Send to more than one provider, review the bounce message and confirm whether the problem is authentication, reputation, storage or an incorrect address. The error text usually tells you where to start.
