mailing alts

[Zojha]

It's like you said and how I feel too, they invisioned this game to be a single character game.

In which case they could have restricted people to one character from the start or grandfathered in legacy players and restricted you to one character when ARR launched and if anyone asked for alts, they could just told people that it's their vision for people to only have one character (and please buy fantasia).

They didn't. In fact, the one-character per server subscription isn't even called the "standard" subscription, but the entry subscription. As such, I doubt it's what they envision.
It took them years to add Frontline Freelancer because they were afraid of "Moral Degradation". I'd not be surprised if they genuinely believe the mail restriction to be a pure anti-RMT measure. Our devs have veeery strange reasoning at times. Unless they gain money from restricting alts somehow, I doubt they feel strongly about it one way or the other.

[Callinon]

Unless they gain money from restricting alts somehow, I doubt they feel strongly about it one way or the other.

They do gain money from restricting alts. Because if people want extra storage space, the only way to do it now is to pay monthly for more retainers.