Deliverability
Postmaster Tools
Free dashboards from mailbox providers, most importantly Google Postmaster Tools, that show how they see your domain: spam rate, reputation, authentication results and delivery errors.
What Google Postmaster Tools shows
- User-reported spam rate, the number Gmail’s bulk sender rules are measured against.
- Whether your domain meets Gmail’s sender requirements.
- SPF, DKIM and DMARC pass rates for mail Gmail received.
- Delivery errors, such as rate limiting or rejections.
How to set it up
Sign in with a Google account, add your sending domain, and verify it with a DNS TXT record. Data appears once you send enough daily volume to Gmail users, usually a few hundred emails a day or more.
Other providers
Microsoft offers SNDS (Smart Network Data Services) for IP reputation at Outlook.com, and Yahoo has its own sender hub. Gmail’s tool is the one to check first, since Gmail is usually the largest share of any list.
Let MailCraft handle the details
Authentication, bounces, complaints and suppression are built in. Start free with 3,000 emails a month, no credit card required.
Start freeRelated terms
Full glossaryDeliverability
Sender reputation
A score mailbox providers maintain for a sending domain or IP based on engagement, complaints and bounces, which determines whether your mail reaches the inbox, spam, or gets rejected outright.
Sending & delivery events
Complaint (FBL / feedback loop)
A signal from a mailbox provider that a recipient marked your email as spam. Feedback loops relay these back to senders so the address can be suppressed.
Deliverability
Bulk sender requirements
The rules Gmail and Yahoo enforce, since 2024, on anyone sending around 5,000 or more emails a day to their users: full authentication, one-click unsubscribe and a low spam rate.