"Use your existing SMTP host..."

I’ve just registered a domain name with a budget host, they have given me a ‘catch-all’ POP3 mailbox, which is fine, but they don’t offer any SMTP service - “Outgoing SMTP host: use your existing setting for this.” - is what their instructions say.
Now how do I go about doing that exactly; assuming that my existing host is smtp.crappyoldhost.net; (I think) because I’m trying to send message from me@mylovelynewdomain.com, they are not having it.

OE6 gives this message:

How can I make this work? I’m sure i’ve done this before with no problems.

It may be that your ISP’s smtp server is not configured to send mail if the from address is not from its domain…

If that is the case you could put your exisiting email address in the from box and put your new address in the reply-to box. Also you could download your own smtp server there are many available for free.

In the last minute or two, I worked out that my ISP expects ‘POP before SMTP’ - i.e. a logged in session to use either (I think).

I just tried it with the default email address I got with my broadband signup and it seems fine there; their SMTP server doesn’t seem to care what is in the from field.

Thanks for your reply anyway Cooper.

Even your own SMTP server may not help; quite a few ISPs block port 25 except through their mail server to minimize spam from their domain.