We are using for few months now sendgrid's click tracking feature and since this morning some of our customers could not be redirected to our platform through Sendgrid generated links.
They have the error :
Safari can't establish a secure connection to the server "u6012831.ct.sendgrid.net"
I cannot reproduce it on my side.
any ideas were it could come from and how to fix that permanently?
We have the same problem. From our side when we test our newsletter (not made with a template from SendGrid but from our own cms / newsletter) we cannot reproduce the problem - besides of these facts: -Thunderbird / Mac shows an similar info, but there you can click 'send it through SendGrid anyway' and it opens the link correctly -Outlook / Windows - there when you allow downloading all the images, then it works too -the link should be implemented into text, not shown as simple url. Implemented into text also Thunderbird of Mac works without any popup information.
On all other mail programs (on Mac, Windows, Android) from our side, it works fine. But some of our customers tells, that no link works on Windows / Outlook or Windows / Thunderbird or Android
Very strange!! And the most annoying problem is that the support of SendGrid very often is absolutely not helpful. Some month go we contacted them and the solution (after waiting at least 2 Weeks of response!): you always can send it not via SendGrid. That may help. Thank you SendGrid!!
I got Sendgrid support's answer to late and so decided to remove the click tracking feature... I think it is because some of our clients have very strong firewall rules, blocking sendgrid domain.
UPDATE:
I received an answer few weeks later. I would like to share it for the one having the same issue :
This is something I have also dealt with when I first started using the system and I have solved this by setting up link branding for my account which helped to hide the wrapping.