LMTP Characteristics
Conformance
Crymap’s LMTP implementation is believed to conform to:
- RFC 1652 (8BITMIME)
- RFC 1830 (BINARY)
- RFC 1854 (PIPELINING)
- RFC 1870 (SIZE)
- RFC 1893 and RFC 2034 (ENHANCEDSTATUSCODES)
- RFC 2033 (LMTP)
- RFC 3207 (STARTTLS)
- RFC 5321 (SMTP)
- RFC 6531 (SMTPUTF8)
Security
Crymap does not implement any authentication mechanism and does not require use of TLS. LMTP is not expected to be used with untrusted sources, as OS-level controls should be sufficient to prevent foreign access to LMTP.
For similar reasons, Crymap LMTP makes no attempt to verify the host name
presented to it in LHLO
and simply records it as-is.
Implementation notes
DOS-style line endings are strictly enforced.
Binary data is correctly processed even if sent through a DATA
command.
Maximum line length is 65534 bytes.
VRFY
and EXPN
are not supported and return constant hardwired responses.
The same limit used for IMAP APPEND is enforced for LMTP.