Hyperlinks work in Preview/Test email, not in actual sent email. ISP issue?

[EmersonAuxiliary]

Hello, our organization just sent an email where all hyperlinks are functional in Preview, Test, and the email URL link, but are not functional in the actual sent email. I believe this issue is linked to our ISP, Xfinity (formerly Comcast), blocking the link rewriting (which I understand is for tracking and compliance).

I tested multiple browsers on my desktop (Chrome, Firefox, Bing) with ad-blockers turned off, also tried incognito mode, and all resulted in the message:

I had a colleague test the same at her location, but she got the same result as she has the same ISP.

I also tested out the hyperlinks on my mobile device (iPhone) using cellular data only and all links opened correctly in Safari. When I tested my mobile device while connected to Xfinity wi-fi, the hyperlinks do not open.

This issue I believe started within the last month, given that the last email we sent on Jan 17 and initially worked (but now doesn't).

Emails are being delivered according to the reporting. The issue is not limited to one particular email. How can this be resolved with Xfinity (large ISP) by Constant Contact? 

[William_A]

Hello @EmersonAuxiliary ,

The "took too long to respond" error is indicating that something is blocking the redirect, or it's getting erroneously caught in some kind of filtering functionality and causing a time-out. Due to the information needed to troubleshoot this connectivity error further, I'd advise calling our general support. They'll need to go over some more technical troubleshooting elements, including:

• capturing the browser's console code errors
• a screen recording from your side of the exact behavior from clicking the link to the error page showing
• A list of browsers, browser plugins / addons / extensions, VPNs, ad/pop-up blockers, and other security software used on your device and organization's network (if applicable).
• A list of the email programs used (Gmail, Outlook, etc.)
• the exact name of the email, and if possible, forwarding it to the address provided by the support team

There may be other troubleshooting questions that phone support and the higher level technical team will ask for, but this at least gives you a head's up on what things you'll want to gather before calling in, in order to save troubleshooting time.