Deliverability Mastery
From sender reputation to Gmail's filter: the full path to understanding why cold email lands in spam and how to reach the inbox reliably.
10 stepsabout 20 min total
What Is Sender Reputation, and How Do You Build It?
Sender reputation is the trust score receiving servers assign your domain and IP. Here is what shapes it, and how to build it deliberately.
The Complete Guide to Email Authentication
How SPF, DKIM, DMARC, and the newer ARC and BIMI standards prove your mail is really yours, and why cold email fails without them.
What Is an SPF Record, and How Do You Set It Up?
SPF is a DNS record listing the servers allowed to send as your domain. Here is how it works, how to set it, and the mistakes that break it.
What Is DKIM, and Why Does It Matter for Cold Email?
DKIM cryptographically signs every message you send so receivers can prove it is really from you and was not altered. Here is how to set it up.
What Is DMARC, and Which Policy Should You Use?
DMARC tells receivers what to do when SPF or DKIM fails, and reports who sends mail in your name. Here is how to roll it out without blocking yourself.
What Is a Good Spam Score for Cold Email?
Spam scores from SpamAssassin, Microsoft SCL, and provider filters decide placement. Here are the target numbers and what actually moves them.
How to Check Your Email Spam Score Before Sending
A pre-send routine to catch authentication gaps, content triggers, and infrastructure problems before a campaign ever reaches a real inbox.
Inbox Placement vs. Deliverability: What's the Difference?
Deliverability means your mail was accepted. Inbox placement means it reached the inbox. Confusing the two hides your real cold email problem.
How Gmail's Spam Filter Actually Works
Gmail decides placement with authentication rules, AI content analysis, and a hard complaint-rate ceiling. Here is what each layer checks, and how to pass it.
Complaint Rate and Bounce Rate: The Numbers That Sink Domains
Two metrics decide whether receivers keep trusting you: how often recipients mark you spam, and how often your mail hits dead addresses.