You can raise your outgoing transaction limit by sending them a message through their site and asking them to raise the limit. You can´t just send them email because they prefer to have the account holders contact them via their site.
This is how you get to the message sending “place” (it´s a bit hard to find, for me it was anyway..)
Log on to your account, press “email support” button, then select “my account” in the messaging center, then click “General ‘My Account’ enquiries”, than a field where you can write your request to upgrade your limit opens.
I just asked them if they could raise my limit. The next day I got an email where they asked me to upload a copy of my drivers licence to their site. I uploaded the document and soon they raised my limit to about 30000usd/90days.
Hope that this helped you.