The largest mailbox providers have tightened their rules. Most apply to everyone; the strictest apply to high-volume senders.
Rules for all senders
- SPF or DKIM must pass for your domain. How to set up an SPF record How to enable DKIM in DirectAdmin
- Valid forward and reverse DNS for the sending server (a platform matter on shared hosting). Reverse DNS (PTR records) explained
- Encrypted connections (TLS) for delivery.
- Low spam complaint rates. Google advises keeping reported spam below 0.1% and never reaching 0.3%.
- Standard message formatting, with a From address you actually control.
Additional rules for bulk senders
Gmail and Yahoo define bulk senders as those sending around 5,000 or more messages a day to their users; Microsoft applies similar rules to Outlook.com, Hotmail and Live addresses at the same scale. They require:
- Both SPF and DKIM, plus a DMARC record
- Alignment: the From domain matches the SPF or DKIM domain
- One-click unsubscribe in marketing messages, honoured within two days
What this means on Traxio
Person-to-person business email and website notifications fall under the rules for all senders. Set up SPF, DKIM and DMARC and you meet them. Set up SPF, DKIM and DMARC
Shared hosting isn’t designed for bulk marketing mail. Send newsletters through a dedicated email marketing service, and authenticate your domain with that service too.
Checking how Gmail sees you
Send a test, open it in Gmail and choose Show original. Google Postmaster Tools gives domain reputation data once you send enough mail to Gmail users for it to register.