Ok,

sendmail is up and running, works perfectly, except.....when I set the config files up, I set the server up to send mail via my isp's mail server, as I understand this helps stop other servers rejecting mails from my server.

Well, the problem I have is that I can send an email to anyone on my isp mails server, but I can send mails to people who use other mail servers?

can anyone help?

Error messages? Returned mail messages? This info helps us determine the problem, if nothing then it can be anything causing the problem.

Well, thats the problem, i'm not getting any errors or returned mails.

sorry

Who have you sent to and have you tested this yourself, get a yahoo or some other account outside your ISP to see for youself? Maybe whoever your sending to their ISP or mailserver is just dropping it, thinking its spam or something along those lines. And is it you can send to anyone on your ISP or outside, cause you've got two "can's" there in your first post.

This may seem silly, but send the emails to yourself. Then if you get them, you can examine the header(s) to see your message being directed out and back.

trickykid is right on the money as well. make an account on yahoo, hotmail, gmail, whatever, and use it for testing.

once your message is accepted by the smtp server at your isp, it will be directed to the recipient's mail server automatically. Their (the ISP's) mail server will do a DNS lookup for an "MX" record and get the IP address of the target mail server, and your message flies off into the ether.