The email deliverability metrics worth tracking
6 min read
The deliverability metrics that matter most are bounce rate, spam complaint rate, inbox placement, authentication pass rate and genuine engagement such as replies and clicks. Delivery rate alone only tells you that a server accepted the message, not whether it reached the inbox. Tracking these together shows how mailbox providers see your sending.
Delivered is not the same as inboxed
A message counts as delivered when the receiving server accepts it. It can still land in spam or a promotions tab. Inbox placement, measured with seed mailboxes you own, fills that gap.
Core metrics
Look at trends over time and by provider rather than single campaigns. A change at one provider often points to a specific issue.
- Bounce rate: hard bounces signal list quality problems and should be removed immediately
- Spam complaint rate: keep it well under the 0.3 percent ceiling Gmail and Yahoo set for bulk senders
- Authentication results: SPF, DKIM and DMARC should pass and align
- Inbox placement: where your messages land in Gmail, Outlook, Yahoo and others
- Engagement: replies, clicks and unsubscribes from real subscribers
A note on open rates
Open rates have become less reliable because some mail clients prefetch images and privacy features hide real opens. Treat opens as a rough indicator and lean more on clicks, replies and conversions.
Using seed mailboxes
Subscribing your own mailboxes at each major provider to your list gives you a direct view of placement and rendering. The extension can work through those seed inboxes, match messages to a campaign through the ESP Connector and keep a local log, which makes regular checks less manual. Activity in seed mailboxes should be used for observation, not to inflate campaign statistics.
Frequently asked questions
What is a good bounce rate?
Lower is better, and consistent hard bounces indicate a list problem. Rather than chasing a universal benchmark, remove hard bounces at once and investigate any rise.
Why do my open rates look unusually high?
Some mail clients load images automatically or through proxies, which can register opens that were not real reads. Clicks and replies are more dependable signals.
Should seed mailbox opens count in my campaign stats?
Ideally exclude them. Seed mailboxes exist to observe placement, and including them can distort engagement data.
Also useful: Email Automate overview · Free email tools