FT_SMTP¶
SMTP protocol filter.
- Category:
Protocol filter
Supported flags
FF_READ_ONLY_OUT
FF_SSL_TLS
FF_SSL_SELF_SIGNED_CERTIFICATE
Object types
OT_SMTP_MAIL_OUTGOING - outgoing mail
- Indicates object parts:
no
The objects contain a mail message in one stream.
When FF_SSL_TLS flag is specified, the library adds FT_SSL filter to a chain automatically after receiving STARTTLS command from mail client.
It is possible to add FT_SSL filter with FF_SSL_TLS_AUTO flag to decode TLS automatically when it starts after the initial plain text handshake.
It makes sense to use FF_READ_ONLY_OUT flag, because the email clients usually have small timeouts, and can break the transfer during filtering a large message in dataAvailable event. If it is necessary to modify/block some outgoing messages, it is possible to return “250 OK” or “554 Transaction failed” status to email client immediately (using OT_RAW_INCOMING object), then retransmit allowed messages via different mail server.
- References: