工具代理资料库Pro
  1. Library
  2. Email Protocols
  3. Sending and Receiving

Sending and Receiving

SMTP (Simple Mail Transfer Protocol)

The 40-year-old protocol that still delivers every email you send—a polite conversation between servers that was designed when the Internet trusted everyone

SMTP Ports Explained

The four SMTP ports exist because email's original design trusted everyone. Each port number tells the story of a problem that needed solving.

IMAP (Internet Message Access Protocol)

IMAP solved email's hardest problem: making one mailbox appear on every device. Your phone, laptop, and tablet aren't holding copies—they're windows into the same place.

POP3 (Post Office Protocol)

The email protocol that treats your mailbox like a physical mailbox—you take the letters out and bring them home

IMAP vs. POP3

POP3 downloads your email to one device. IMAP keeps it on the server so every device sees the same inbox. One philosophy won.

Exchange, ActiveSync, and MAPI

Why Microsoft built proprietary email protocols—and when standard ones aren't enough for how work actually happens.

此页面对您有帮助吗?

😔
🤨
😃

网络工具

  • 端口检查器
  • DNS 查询
  • Ping
  • SSL/TLS 检查器
  • WHOIS 查询
  • Fetch
  • 我的IP地址是什么

学习

  • 资料库
  • 端口
  • 联系我们

公司

  • 关于
  • 网格

安全

  • 服务条款
  • 隐私政策

© 2022–2026 Connected Systems, LLC. 保留所有权利。