It can, but it is the "old school" type of quoting.
You're right, "old school" :-)
Anyway I explained myself bad. I simply need to include original text in reply, it doesn't matter if plain text (so with "<") or RTF. I mean like a normal email client: my new text has to be written above the original text.
Currently using iPGMail (your competitor) I have to:
1. open Mail app;
2. copy encrypted text;
3. open iPGMail;
4. Decode -> Import -> input pw to do decryption
5. open generated txt -> copy all text
6. Compose -> paste.
7. Pasted text is normal text, so the email client of recipient will NOT show it as "original" text.
Aside problem in point n. 7, the whole procedure is very long and complex. Does Secumail brings advantages with respect to this?