Reference
What is Deliverability?
Deliverability is whether your email reaches the inbox rather than spam or nowhere. It is decided mostly by domain authentication and sending reputation, not by the content of the message, and a sender rarely sees when it fails.
Also called: email deliverability · inbox placement
What decides it
- SPF, DKIM and DMARC alignment on the sending domain
- The reputation of the sending IP and domain over time
- Recipient engagement — messages people open and reply to
- Complaint and bounce rates
- Whether the from address matches the domain the recipient expects
The silent failure
Mail routed to spam produces no bounce and no error. An order confirmation system can fail for months while the sending code reports success on every message, and the first signal is a customer asking where their receipt went.
How to test before launch
Send a real message to a Gmail and an Outlook address and check the inbox rather than the sent folder. Read the headers and confirm SPF, DKIM and DMARC all pass. It takes five minutes and it is skipped on most builds.
Where this is covered in depth
A definition can only go so far. E-commerce website development: what the whole build actually involves covers this properly — 7 minutes, free, no email required.
Who wrote this
Anas Bin Masud builds e-commerce sites and does technical SEO for businesses in the UK, Canada and Pakistan. These definitions come from client work rather than from a content brief — where an entry describes a mistake, it is usually one found on a real site. More about how I work.