FIOS G3100 is blocking some IP addresses or Certificates from FASTMAIL

[SteelerNation]

I know the FIOS G3100 uses McAfee network protection. When enabled, FIOS is blocking some IP addresses or Certificates from Fastmail. I can no longer see images in Fastmail. If I turn off network protection, or if I connect via another network, I CAN see images.

Specific error is NET::ERR_CERT_COMMON_NAME_INVALID

This error only happens when accessing Fastmail over a FIOS network, with MCAFEE Network Protection enabled.

PLEASE HELP!!!!

[SteelerNation]

@McAfee Network Protection appears to be blocking something related to www.fastmailusercontent.com

What? I have no clue, all I know is when I go to this site, without McAfee Network Protection enabled, everything works. BUT with McAfee Network Protection enabled, I get the following Error:

www.fastmailusercontent.com uses encryption to protect your information. When Chrome tried to connect to www.fastmailusercontent.com this time, the website sent back unusual and incorrect credentials. This may happen when an attacker is trying to pretend to be www.fastmailusercontent.com, or a Wi-Fi sign-in screen has interrupted the connection. Your information is still secure because Chrome stopped the connection before any data was exchanged.

You can't visit www.fastmailusercontent.com right now because the website uses HSTS. Network errors and attacks are usually temporary, so this page will probably work later.

[Cang_Household]

Since McAFee is providing that part of the firmware, why don't you contact McAFee directly to reclassify the domain name as safe?

[SteelerNation]

Did that, McAfee said, "Where is this installed on your PC?"

I said, "It's on my router."

They said, "Let me control your PC and take care of it"

I said, "It's not on my PC, but okay."

They had me go through installing the support software, then tried to get into my computer programs, etc. And asked, "Where is McAfee installed." 

I said, "It isn't - It's on my router."

They said, "Who is your internet service provider?"

I said "Fios"

They said, "Why are you talking to us? You need to talk to FIOS!"

I called Fios, they said, "Please call McAfee"

And around and around we went.

[Cang_Household]

Fios loads McAFee's program. If McAFee's program blocks some websites, you need to talk to them to modify the program. I am not sure there's another support channel for these kind of programs distributed to the ISPs. I can do some research, but will be slow.

[SteelerNation]

McAfee certainly provides no support in their consumer support system.  

This is frustrating,  to say the least. 

Thanks for any help you can provide.