Ok. Good to know.
Otherwise.. the bot will simply take the first 40chars of the first line of a message and use that as the Subj to fido. So, even though you got the --Subj: -- command wrong, it took "?SUBJ:? Telegram bots" as part of the new subject because that is what you placed within the first 40chars of your message anyway.
--- tg BBS v0.6.2
* Origin: Fido by Telegram BBS by Stas Mishchenkov (2:460/58)