Hello Michael,
I tried the same kind of thing few months back but unfortunately couldn't find any reasonable solution for it and I had to create the folder and set the permission by hand.
If all the recipients know what you are sending them and they are likely to read and respond to those emails then there is no problem in sending that many emails but if most of them don't read the emails or don't respond to the email then it is likely that the account will be blacklisted.
I am using SpamTitan for more than a year and I haven't face any problem till date. If I would need to switch to another one then I will definitely give your program ago :)
It seems that your hosting plan has been expired. You just need to make payment to your hosting provider in order to keep your website running as it is previously.
Are you doing installation on a shared computer or is your computer in a network group. If you are not in a network then it should be working fine except if you have problem with your internet or login info.