I know theres a lot of threads re: outgoing mail servers..
Haven't found the answer yet..
Setting up my own domain on my iOS, but need an outgoing mail server that will work on any network (wifi or 3g)
That's because you need to use the SMTP server (from context it sounds like you're using a mail account that uses SMTP for outbound mail) the your mail provider provides for your domain. There's no one-size-fits-all answer. Contact your mail provider/host if you don't have the info. We can't give it to you.
A lot of ISP's prevent use of their SMTP servers if you're not connected through them as an antispam measure. Some will allow such access with authentication. Check and see if your provider does. If not then find a mail provider that meets your needs.
Is the only solution to forward my mail to iCloud? and use that?
No, see above. Additionally, your ISP, hosting provider and even your email provider don't have to be the same. You can modify your MX records to use an email provider other than your hosting provider should you decide to take that route. There are many, many options other than just forwarding to iCloud.
Looking for a better suggestions...
Clarify exactly what you mean by "better". Every option has its pros and cons and what's better for you isn't necessarily better for the next person. Again, it's not a one-size-fits-all matter.
