SMTP

From Protocolinfo

SMTP is Simple Mail Transfer Protocol, as defined in RFC 2821 (see also RFC 1869). This is the protocol used for sending e-mail.

Contents 1 Identification 1.1 Ports 1.2 l7-filter 2 See also

[edit] Identification

[edit] Ports

Servers:

• [IN/OUT] TCP 25 - SMTP sending and receiving mail.
• [IN/OUT] TCP 587 - Submission protocol - typically used for relaying inbound mail from clients.
• [IN/OUT] TCP 465 - SSL SMTP - secure sessions of inbound mail from clients.

Clients:

• [OUT] TCP 25 - SMTP outgoing mail. (generally used)
• [OUT] TCP 587 - Relaying outgoing mail.
• [OUT] TCP 465 - SSL SMTP.

[edit] l7-filter

l7-filter uses the smtp pattern. It is well tested.

[edit] See also

• Wikipedia's SMTP article
• Wikipedia's E-mail Client article