花了400多在厦门这家店吃海鲜 有老鼠在脚下相陪
Simple Mail Transfer Protocol (????? ?????: SMTP; ?????? ?????: ???????? ???? ?????? ????) ??? ????????? ???????? ?????? ???? ???????? ??? ????????.
????? ?????????
[????? ??? ???? | ?????]SMTP ???? ?????? ???? ???????? ??? ????? ?????, ?? ????? ???? ????, ?? ???? ????? ?????? ????? ?? ?????? ????? ???????? ???? ?? ????. ?????? ?????????? ????? ???????? ?????? ?? ?????? ????, ???? POP3 ?-IMAP.
??? ???????? ???????? (??? ??????). ????? ????? ??????? ?????????? ?????? ?? ??? ????? ?? ?????? ??????. ???? ???? ???? ????? ????? ??? ?? ????? ????? ?? ??? ????? ??????? ??????. ???? ?? ???? ?????? ?? ???? ?????? ???? ????? ?-MIME.
SMTP ???? ??? TCP ?????? ???? ??? ????? 25. ???? ????? ?????? ??? ???? 587. SMTPS ??? ????? SMTP ????? ??????? SSL ?????? ???? ??? ????? 465.
?????? ?? ???????? SMTP ?????? ?-1982 (????? RFC 821). ???? ???????? ?? ???????? ??? ?????? ARPANet, ????? ?????? ??????. ?????? ??? ?????? ??? ???? ?????? ?????? ????? '???' ???? ???? ????, ??? ??? "?????" ("From"). ????? ?? ?????? ??? ??? ????? ??????? ??? ????? ????, ?? ????? ?? ????????? ????? ??? ???? ???????. ?????? ???? ?????? ??? ????? ??????? ?? ?????, ???? ???? ?-DomainKeys.
???????? SMTP ????? ???? 2008 ??????? ESMTP (????? RFC 5321) ????? ???? ?????? ?????? ?? ????????? ?????? ?? ?????? ??????. ???????? ?? ???? ?????? ???? ????.
????? ??? SMTP ?????? ?-DNS
[????? ??? ???? | ?????]????? ??? ?-SMTP ????? ???? ?????? ?????? ?????? ?? ?????? ???? ?? ??? ???? DNS ???? MX (Mail eXchange). ????? ?????? ???? ???? MX ???, ?????? ???? ?? ???? ??? ??????? ?????? ????? (????? ????? ?????) ????? ???????? ???? ????? ?? ???? ??????, ????? ????? Round Robin ?? ??????.
??? ??, ????? ???? ??????? ????????? ?-DNS ?? ??? ????? ???? ???? ?? ???? ??? ????? ??? ????? ?????. ???? ?????? ???? ?????? ????? ????? ??? ????? ?? ????. ?????? ?? ??? ??? ?????????? ?? ???? SMTP ?? ????? ???? ???? ?????????. ?????, ???? ??????? ???? ?????? ?? ????? TXT ?? ????? ?? ????? ?????? ??? ????? ?????? ???? ????????. ???? ????? ?? ????? "????? SPF".
????? ????? ? SMTP
[????? ??? ???? | ?????]SMTP ??? ??????? ???? ??????? ??????? ?? ??????? ?????? ????? ?? ?????? ????? ???? ???? ?????? ?????????? ??? ??????????? ??????? ????????? ????. ??? ????? ?????? ?? ????????? ???? ?????:
- ??????: ????????? ????? ???? ??? ?? ????? ?????? ?????? ????? ???? ???? ????? ?? ?? ?????? ??? ?? ?????.
- ?????: ????????? ????? ???? ??? ?? ??? ?? ????? ????? ?? ????? ????? ?? ????? ???? ??????? ???? ?? ????? ?? ????? ????.
- ??????: ????? ???? ?????? ??? ?? ?????? (???? ??? ????? ????) ?? ????? ???? Spoofing ????? ?????.
????? ????? ? SMTP
[????? ??? ???? | ?????]- Relay Control: ???? ???? ?????? ????? ?????? ????? ?? ????? ???? ??? ????? ??????, ????? ???? ??????? ???????? ?? ??? ??????? ??????? ????? ?????.
- Harvesting Control: ????? ?? ????? ???? ???? ???????? ???? ???? ?????? ?????? ?????? ?? ??? ???? ????? ?? ?????? ??????.
- Reverse Lookup: ????? ?? ???? ????? ?????? IP ?? ? MX ?? ??? ???? ????? ?????? ?????? ?????? ???? ?????, ?????? ???????? ???? ??????? ???? ???? ????? ?????? ????, ????? ?????? False Positive ???? ????? ?????.
- TLS: ????? ????? ??? ??? ???? ????, ?????? ????? ????? ?????? ?????? ??????? ??? ????? ?"??????" ?? ?? ?? ?? ?????? Self Signed ??? ????? ????? "??????"
- SPF: ????? ????? DNS ?????? ?? ?????? ?? ???? ????? ??????? ????? ???? ???? ??? ???? ????? ????? ????? ????? ??? ????? ????? ?????? ??? ??????.
- DKIM: ????? ???????? ????? ???? ???? ????? ???? ????? ?? ????? ?????? ?????, ?????? ????? ????? ???? ?????? ??????? ????? ????? DNS.
- DMARC: ????? ?? ?????? ????? ?????? ????? ????? ?????? ????? ???? ????? ???? ????? ?????? SPF ?/?? DKIM.
????? ????? ?-SMTP
[????? ??? ???? | ?????]???? ????? ?????? ??????, ??? ????? ??? SMTP, ??? ???? ????? ??????? ?-HELO ??????? ?? ????? ?? ???? ????? ?????? ????. ????:
HELO mydomain.com
???? ???, ???? "MAIL FROM" ?????? ????? ?? ?????, ?? ??? ????? ?????? ?????? ????? ????. ????:
MAIL FROM:<romeo@bogus.net>
???? ??? ???? "RCPT TO" ?? ????? ????. ????:
RCPT TO:<juliet@fakenet.com>
?????? DATA ?????? ?? ????? ????? ?????. ???? ????? ????? ???? ????? ?? ??? ?????. ????:
DATA
I`m sorry to say that I want to leave you.
.
????? ?? ??? ????? ?? ???????? ????:
QUIT
??? ??
[????? ??? ???? | ?????]??????? ????????
[????? ??? ???? | ?????]
| ????? ?????????? ?? ?? ???? ??OSI | ||
|---|---|---|
| ???? ?????? | HTTP ? SMTP ? FTP ? RTP ? IRC ? SNMP ? SIP ? DNS ? DHCP | |
| ???? ?????? | MIME ? ASCII ? Unicode ? TLS | |
| ???? ????? | ASP ? PPTP ? SSH ? NFS ? RPC ? SOCKS | |
| ???? ??????? | TCP ? UDP ? SCTP ? DCCP | |
| ???? ???? | IP (IPv4 ? IPv6) ? ICMP ? IPX ? ????? | |
| ???? ??? | ????? ? Token ring ? FDDI | |
| ????? ?????? | E1 ? 10Base-T ? RS-232 ? DSL ? SONET | |
| ?????????? ????? TCP/IP | ||
|---|---|---|
| ???? ????? | HTTP ? SMTP ? FTP ? DNS ? DHCP ? SSH ? RTP ? RTSP ? IRC ? SNMP ? SIP ? IMAP4 ? MIME ? Telnet ? RPC ? SOAP ? LDAP | |
| ???? ?????? | TCP ? UDP ? SCTP ? DCCP | |
| ???? ??? | IP ? IPv4 ? IPv6 ? ICMP ? IPX ? IGMP | |
| ???? ??? | ????? ? 10BASE-T ? 802.11 WiFi ? Token ring ? FDDI ? ARP | |