fttImplicitTLS

fttImplicitTLS = 1

Example

function UsesTLSFromConnect(Mode: TvxTLSType): Boolean;
begin
  Result := Mode = fttImplicitTLS;
end;

Usage

fttImplicitTLS starts SMTP, FTP, POP3 or IMAP transport encryption immediately when the TCP connection is established.

Additional Technical Info

fttImplicitTLS is ordinal 1 of TvxTLSType. Velox maps it directly to Indy utUseImplicitTLS for SMTP, FTP, POP3 and IMAP. Setup and transport objects currently default to this mode.

TLS negotiation begins as soon as the socket connects; no plaintext protocol greeting or STARTTLS command occurs first. Indy can replace a regular/explicit port with its protocol-specific implicit TLS port. Confirm the configured port because a server expecting plaintext/STARTTLS on that port will fail the connection.

This mode does not choose the TLS version or prove certificate/hostname validation. Configure those independently and reject obsolete protocol settings. A handshake failure stops the connection.

The example only compares metadata and was source-reviewed; no TLS, network, certificate, runtime or image test ran.

External references

• Indy TIdUseTLS source.

Created 2026-07-15