SMTP <https://datatracker.ietf.org/doc/html/rfc2821#section-4.1.1....> is pretty clear that the message termination sequence is CR LF . CR LF, not LF . LF, and disagreements in this spot are known to cause problems (include undesirable message injection). But then enough alternative implementations that recognize LF . LF as well are out there, so maybe the original SMTP rules do not matter anymore.
This is covered in the article you didn't bother to read before commenting on,
> Even if an established protocol (HTTP, SMTP, CSV, FTP) technically requires CRLF as a line ending, do not comply. Send only NL. Almost all implementations of these protocols will accept a bare NL as an end-of-line mark, even if it is technically incorrect. Give no quarter to the tyranny of CRLF.
"Please don't comment on whether someone read an article. "Did you even read the article? It mentions that" can be shortened to "The article mentions that.""
