Who are the main players in email delivery?

Main players divide into categories: senders (your organization), sending infrastructure (ESPs, **SMTP** providers, MTAs), receiving infrastructure (Mailbox Providers like **Gmail**, **Microsoft**, **Yahoo**), reputation arbiters (blocklists, anti-abuse networks), and standards bodies (**IETF**, **M3AAWG**).

Senders create and trigger emails. ESPs provide sending platforms with analytics and compliance features. **SMTP** providers offer infrastructure for transmitting messages. Mailbox providers receive, filter, and store emails for recipients. Blocklists track bad actors. Standards organizations establish protocols everyone follows.

These players interact constantly. Your **ESP** connects to MBPs over **SMTP**. MBPs consult blocklists during filtering. Anti-abuse networks share threat intelligence. Standards bodies publish protocols (**SPF**, **DKIM**, **DMARC**) that everyone implements. Understanding these relationships helps diagnose delivery issues.