Diane,

How can one send to 500 people if one's ISP limits messages to about 50
recipients per message? I just had someone tell me that he has to break down
his email blast to his clients into groups of 25-30 or they will not send.
He has almost 500 people to whom he sends a monthly update.

No, he is not a spammer. These people are his legitimate clients.

Gregg Hill