What is Sender Identity?
The verified domain or address a provider is permitted to send from, proven through DNS records. BYOB projects verify sending domains before campaigns so transactional mail leaves from a trusted name.
Related terms
DNS Verification (TXT)
Proving domain ownership by publishing a provider-issued token as a DNS TXT record. BYOB custom-domain and sender setup both use this challenge before activating routing or sending.
Return-Path Alignment
Matching the envelope sender domain used for SPF with the visible From domain that recipients see. Aligned domains let inbox providers credit authentication to the brand instead of the sending platform.
Sender Reputation
The trust score mailbox providers assign to a sending domain or IP from engagement, complaints, and authentication history. High reputation lands in the inbox; low reputation diverts identical content to spam.
Complaint Feedback Loop
A mailbox-provider channel reporting when recipients mark mail as spam, so senders can suppress complainers immediately. Ignoring complaints burns sender reputation far faster than any single campaign gains.
Email Warmup
Gradually increasing send volume from a new domain or IP to build a positive reputation history. Patient ramp-ups with engaged recipients earn inbox placement that sudden blasts destroy.
Transactional vs Marketing Email
Account messages users expect (receipts, resets, alerts) versus promotional campaigns needing consent and easy opt-out. Separating the streams protects critical delivery when marketing complaints spike.