1. Mandatory Email Authentication (Now Enforced)
Google and Yahoo require email authentication protocols to deliver messages to the inbox.
Ensure all three records are set:
SPF
DKIM
DMARC (required since February 2024 for bulk senders)
Use tools like Google Admin Toolbox to verify setup.
2. Unsubscribe Links Are Now Mandatory
Bulk senders must include a one-click unsubscribe link. Non-compliance leads to deliverability penalties or outright blocks.
Best Practice:
Add a clear and visible “Unsubscribe” or “Opt-out” link in all emails.
Avoid deceptive language like “Update preferences” or hiding the link in footers.
3. Manage Sending Volume Carefully
Over-sending is one of the fastest ways to burn a domain.
Recommended Limits:
30–50 cold emails per inbox/day (depending on warm-up status).
Use inbox rotation to send at scale across multiple domains.
4. Avoid Overuse of Tracking Tools
Excessive use of open and click tracking can trigger spam filters, especially if both are used simultaneously or embedded in bulk.
Tips:
Use only one tracker (open or click or avoid using Open tracking at all).
Avoid link shorteners like Bit.ly.
Plain-text emails = better trust + fewer tracking red flags.