to send real gsm sms you need a connection into a network, or an aggregator, or a partner of an aggregator - anything you get for free is either likely to be dodgy or fall on it's arse with zero reliability.
we pay per message and send our stuff through t-mobile in the uk this gives us premium quality messaging, very fast with delivery reports so we know when the handset has received the message. well worth the extra but we're a premium rate sms company so it does pay for itself instantly.
we also know that the data we are sending is safe and the numbers we send messages to will not get spammed with junk texts......... some companies will market to the numbers you put through
as for what weedpacket says about charging, yes, too damn right! in terms of pricing expect to pay from a penny per message through to ten pence per message depending on the quality and quantity you want.
anyone charging more than 10 pence per message is either taking the piss, not doing enough volume for them to be getting the messages at a better cost or the order you're placing is for too few messages for it to be worth their efforts.
you can send 100000 msgs through an asian network for little cost but there's not likely to be delivery reports or much reliability or you can buy 100000 msgs, pay more and get a better level of service, quicker delivery and confirmation reports.
personally i'd laff in the face of anyone who tried to sell me sms without confirmation reports
