I'd guess that she used a local email provider (probably an email address provided by per ISP or another local email host), but their servers were down either b

I'd guess that she used a local email provider (probably an email address provided by per ISP or another local email host), but their servers were down either because of the load (everybody was not trying to send emails), or their servers were down as well. Another possible option is that only her mobile internet worked and she didn't have email on her phone, thus she had to use facebook and now thinks my email doesn't work when it's needed.