Do you see those three dots at the end of the Subject? They are called, as you know, an ellipsis.
Now, that I know, both in English and Italian it must consist of exactly three dots, although in informal texts some people often use an arbitrary number of them to convey a stronger idea of suspension. Incidentally, I never do.
Speaking of people, I have had exactly two "serious" relationships, respectively with one girl of approximately my age (actually, about one year older) and with one considerably younger (nearly seven years). Now, the former, who was used to write letters on paper and often used those multiple dots, tended to do so also e.g. in emails, while the latter grown much more in a cell phone and sms era, uses quite often just two dots in smses both for space saving and typing speed, and tends to do so in emails too, although there those constraints are not relevant at all.
Oh well, I know my statistical sample is quite small... but it's something I've been thinking about for a while.