Iridium is the only real worldwide sat
phone.
Globalstar is very patchy
offshore and anywhere outside N America.
I used an Iridium phone for several years for downloading emails. I used mailasail.com
compression software. If you don't then you'll find it expensive!
You may also find the new Spot Messenger (based on Globalstar) useful if you only want to let people know where you are and as an
emergency phone. Again I used that successfully to keep
family informed of our position when doing the Swiftsure this year.
Hope this helps
Richard Woods of Woods Designs
www.sailingcatamarans.com