Large Amounts of Subdomains in File

[harbinc]

I have a program that I monitor that has over 100k+ subdomains. I will be using dnsReaper with the file option. Are there any recommendations for scanning such a large number of domains in a text file? And should I be concerned with DNS request timeouts or getting rate limited? If so please give me your best advise on how to scan a large number of sub domains in a text file and to do so without getting my DNS request blocked.

Thanks for the great app. I love it, and have tested on other projects.