Hi,

Moz is hosted on Amazon. See this sample log entry from today:

54.146.235.41 - - [17/Sep/2017:09:48:13 +0200] "GET /best-deals.html/page/12/ HTTP/1.0" 200 15803 "-" "rogerbot/1.2 (https://moz.com/help/guides/moz-procedures/what-is-rogerbot, rogerbot-crawler+aardwolf-production-crawler-97@moz.com)"[XF 54.146.235.41]

That IP is part of Amazon's ASN.

whois -h whois.radb.net -- '-i origin AS16509' | grep ^route

You can either use something like mod_authz to allow the domain amazonaws.com to connect or you can get each IP from AS16509 and allow that.

Hope it helps.

Regards

Chris