Below, we’ll go over both ESMTP and SMTP commands. Do I even need to know SMTP commands? Yes: If you’re an email developer, you need to know SMTP commands. But if you’re a regular Gmail account user, you can probably save your brain space for random Game of Thrones trivia. ...
Protocol events occur when SMTP commands are either received or transmitted over the network. These events occur when: A client SMTP service or mail user agent uses SMTP to transmit messages for delivery to the local service. The SMTP service relays messages to other SMTP services. Transport Even...
503 Bad sequence of commands 504 Command parameter not implemented 550 Requested action not taken: mailbox unavailable (e.g., mailbox not found, no access, or command rejected for policy reasons) 551 User not local; please try <forward-path> (See Section 3.4) 552 Requested mail action abort...
The 500 series starts with errors in issuing SMTP commands like the following examples: SMTP code Description Meaning 500 Syntax error, command unrecognized The receiving server does not recognize the command. If your server is using antivirus or firewall software, try disabling them before sending...
SMTP commands are predefined text-based instructions that tell a client or server what to do and how to handle any accompanying data. Think of them as buttons the client can press to get the server to accept data correctly. HELO/EHLO: These commands say "Hello" and start off the SMTP con...
SMTP commands are predefined text-based instructions that tell a client or server what to do and how to handle any accompanying data. Think of them as buttons the client can press to get the server to accept data correctly. HELO/EHLO: These commands say "Hello" and start off the SMTP con...
SMTP commands 展開表格 SMTP command Command function HELO Sent by a client to identify itself, usually with a domain name. EHLO Enables the server to identify its support for Extended Simple Mail Transfer Protocol (ESMTP) commands. MAIL FROM Identifies the sender of the message; used in th...
503 Bad sequence of commands 504 Command parameter not implemented 550 Requested action not taken: mailbox unavailable (e.g., mailbox not found, no access, or command rejected for policy reasons) 551 User not local; please try <forward-path> (See Section 3.4) ...
5031. Polite People Say Helo First 2. Error: Need Mail Command 3. Need Mail Before Rcpt 4. Bad Sequence of CommandsSMTP指令顺序出错,一般出现在其他错误之后,先检查之前出现的错误提示 这类问题通常是寄件用 SMTP 软件设计不良或是防火墙造成替 SMTP 软件更新版本并检查防火墙是否有阻止某些指令 ...
503 Bad sequence of commands 504 Command parameter not implemented 211 System status, or system help reply 214 Help message [Information on how to use the receiver or the meaning of a particular non-standard command; this reply is useful only to the human user] ...