You need more information and screenshots or the links they are seeing. What type of program are they using?
Are you using branded tracking or not?
I don't think it's a good idea as I might end up with loads of anonymous activities that will not be added to the lead's activity.
Of course: you turn off mkt_tok, you're turning off web session association.
I see no reason to believe ahead of time the mkt_tok query param is causing the problem. More likely, it's the domain (like Josh asked, are you using a branding domain, and what is that exact domain?). But you'd have to give us more info as to the error they're seeing (again, just dittoing Josh) like "This site is blocked because its SSL certificate is broken" or who-knows-what... we need more info.
I don't have much more info as it was brought to my attention by someone else.
From what I understand, as the IP is being tracked, the internal system is blocking the site. They get a message saying that the page is not available for them because of a security issue and is blocked.
Some links go to my website www.presidion.com and others go to external articles in webs like Forbes, etc. They are having issues with the first ones but I'm not sure about the other ones, I don't think they've clicked in every single link in the newsletter.
I think I'll create a separate email for them with no tracking code to test. Will turning off mkt_tok be enough or better stop the tracking all together?
I sent a test to someone I know their security system is pretty solid. I sent links with tracking code and mkt_token, with only tracking and with everything turned off.
The system is adding something at the beginning of the URL and with Edge he can't open anything, but if he sets Chrome as the default browser all the links are working fine.