E-Signature: Which IP addresses does JotForm use to store signature image?

Our office users are using Windows-based computers with Outlook 2007.  Their web browsers are configured to use a local proxy server that uses Active Directory authentication and ports 80/443 are blocked outbound on our firewall, so they must use the proxy to get out to web sites.  For form submission confirmation e-mail that come into their Outlook, there is a signature capture that happens on one particular form and the signature graphic is embedded in the e-mail.  However, the signature graphic will not load for users who are forced to use the proxy server.  We have tried whitelisting www.jotformpro.com and www.jotform.com on our firewall but because those hosts resolve to multiple IPs (probably for high availability) the signatures only load up intermittently because the PC may resolve to a different IP than our firewall when it routes the traffic.  Is there a list of IPs that we can whitelist that are related to the www.jotformpro.com or whatever host is needed to get the signature graphic?  Two IPs that I see that are used are 104.25.115.9 and 104.25.114.9.

I will forward your request to our second level since I cannot find an IP range that the widget uses, I can only see the domain is the one where you're logged in, for example, www.jotform.com. 

Our developers may let  us know the specific IPs or range of IP addresses that widget uses so you can whitelist them. 

We will let you know as soon as we get any update about it. 

Kevin_G,

Has your second level come back with anything?

Hello Masao,

Unfortunately we have not received any update from our backend team yet. I have sent a note to them asking for an update. We will get back to you as soon as we have any update from them.

Thank you!

Have there been any updates?

Hello Masao,

Unfortunately no. Let me send a message to the widget team to send you the required information.

Thank you!

Hi, terrible support.  Any updates you're not going to tell me about regarding the original question?  Or would you like to just respond with another generic message saying someone is looking into it?

Please, accept our sincere apologies. 

Do note that our second level (developers) are always busy working on other tickets (either feature requests or bugs) and they are also worked in priority order, this is why we have not received any update about it; however, we will ask for any update on the ticket, hopefully we will be updated as soon as possible. 

Thank you for your understanding. 

Can you at least be truthful and tell me that we're never going to get an answer?  I'd rather hear that than nothing and having to remember to follow up.

Apologies for the delay this has taken to get answered. 

Unfortunately, we cannot ensure this will or will not be answered, the ticket is still opened so you should be updated via this thread. 

I can only request an update, hopefully we will get an update as soon as possible. 

Thanks.