Blog
Email Deliverability Guides & Best Practices
Guides, best practices, and intelligence from the InboxEagle team to help you land in the inbox every time.
Gmail6 min
Gmail Deliverability Troubleshooting Guide
Gmail can accept a campaign and still file it in spam. This is the order to check Compliance status, the Postmaster spam rate, and authentication before you rewrite the creative or change ESPs.
Delivery3 min
Hard Bounce vs Soft Bounce for Deliverability
A hard bounce is a permanent failure. A soft bounce is temporary. Here is how eCommerce senders tell them apart, what Klaviyo suppresses, and which bounce should stop the next send.
E-commerce3 min
How to Recover After an IP Warmup Failure
If inbox placement or bounces break while you are still raising volume, stop the ramp. Sending more mail does not build reputation faster.
Klaviyo3 min
Klaviyo vs Amazon SES for Deliverability
Klaviyo and Amazon SES put reputation in different places. One is a marketing platform with shared infrastructure. The other is infrastructure you operate. Neither one shows the Gmail folder by itself.
Authentication3 min
How to Move DMARC from Monitoring to Enforcement
Start at p=none, make every real source align, then tighten policy. p=reject is not a Gmail requirement, and RFC 9989 warns it can break mail you still need.
Gmail3 min
How to Monitor Deliverability at Gmail, Yahoo, and Outlook
Gmail, Yahoo, and Outlook do not share one dashboard. Here is which official tool covers which signal, and what a seed test adds for Gmail, Yahoo, AOL, and Outlook.
Authentication3 min
Multiple DKIM Selectors: When to Use Each
Each sending service should sign with its own DKIM selector. Sharing one selector name means one DNS key, and rotation then breaks the other sender.
E-commerce4 min
Why Order Confirmation Emails Go to Spam
Order mail goes to spam when it shares a reputation with marketing, or when the transactional sender is not authenticated. Here is how to tell those apart and keep receipts delivering.
Gmail3 min
Why Inbox Placement Differs by Mailbox Provider
The same campaign can hit the Gmail inbox, Yahoo spam, and an Outlook rejection. Here is how to tell a provider-specific problem from a broken program.
E-commerce3 min
Why Purchased Email Lists Damage Deliverability
Bought addresses did not ask for your mail. They bounce, they complain, and they are how pristine spam traps get onto a domain that used to be fine.
E-commerce4 min
How Long Sender Reputation Takes to Recover
Mailbox providers do not publish a recovery clock for IP or domain reputation. Here is what is actually documented, and what to do while you wait.
Delivery4 min
SMTP 4xx vs 5xx: How to Read a Delivery Error
A 4xx code means try again. A 5xx code means the receiver rejected the message. Here is how to read SMTP errors when authentication already passes.