It's
earthnet - not earthlink.
The OP set that straight in one of his posts. I checked Earthnet sites, and yes, they only offer Port 80 if Port 25 is blocked by the ISP...
totally stupid.
So the OP is using Earthnet as mail-provider and some other ISP to connect to internet. And this ISP is blocking port 25 as some others do also...
The best thing I can think of would be this:
Create a gmail-account for your girlfriend and set her earthnet account to forwarding incoming emails to this gmail-address.
Use the gmail account to send emails.
After a while everybody will be aware of the new mail-address and you can happily delete this crappy earthnet-thing completely.