Oil boiler flue vent pipe

Oil boiler-vented straight thru to roof- is this corrugated stainless steel ever acceptable in this application. I have contacted the oil boiler manufacturer for their specifications- haven’t got answer- manuals not particularly helpful- no cap either. Thoughts?

99.999% of the time HELL NO!!!

Thx- what I thought - just wanted confirmation

Naw!..IMHO