I used to send email campaigns with SendFox. Recently, despite following all of the troubleshooting steps (from SendFox support and available on the internet), my recipients never receive my outgoing mails. Additionally, despite using verified domains which work perfectly with other mailers, emails sent with SendFox always end up in junk/spam.
Definitely stay away from this product (be sure to sort the reviews with the most recent ones first, and spot the trend for yourself).