I thought about this, and it is a simple process to get your own domain, and use Google Apps to attach your domain to their Gmail, should you so wish. I'm sorry, but I use Gmail all the time, for personal and business, and wouldn't use iBurst's email if you paid me. When I did use it, it was slow, and the 10MB limit was just plain pitiful.
I wasn't referring to the quality of service, just to the email address. If you can get your own domain, register it with your own name and data, and link it to Gmail, I'm sure that would work.
However most domain hosts, like these $5 per month hosts, offer 200GB storage services with their own email panels,
their own spam filters and so on. Why have Google read your email and keep it on their servers, when for R40 pm you can have a 20GB or 100GB mailbox
(IMAP/POP) and webbased too.
If you're dealing in business emails I think own domain or a non-free domain is a must. I would simply NOT trust any1 with a Hotmail/Yahoo/Gmail account
to do confidential business or probably any business at all with. OK, they may know you from elsewhere but if you're hoping to attract business from the web, with all the Nigerian scams around a domain based or an ISP based email
is a must.
Yeah I know 10MB is crap.

MWEB give you 2GB and it's local too, with a
decent anti-spam filter etc - it costs the same as iBurst.