Good question, for me personally both is important. Some of my PSAs and CSAs feel more comfortable with questions through direct e-mailing. Some of them do not have the courage yet to do so through SFI mailing. Once they feel more comfortable, SFI mailing is the way to go! Then they feel more secure. There is so much money-making schemes and frauds online, that sometimes direct personal e-mailing make them feel more at ease.
