In my opinion it is worthwhile to send individual welcome letter to new PSAs becoze it will give honour to him.Also his thinking about his/her leader will be more batter and may possible he would be a future example for his/her team.By sending group mailing to PSA will not more effective.May be he will not consider it so important.there are many other sources are available to inform i.e .Facebook,Twitter and whatsapp, but most effective is the individual welcome letter.
