This is happening to us as well
Links to lead activity within alerts do expire after a defined period of time. In Admin, click on "Login Settings > Edit URL Expiration" to change this setting:
Wondefully helpful - thank you, Dan!! Just curious, any particular reason for this? Does it tax the system to leave a bunch of populated alerts out there? Not a big deal, just curious - I've increased ours to the max. Thank you!
I suspect it's for data privacy reasons. It would open up Marketo to some scrutiny if all of our real-time alerts contained access (without login) to customer lead records with no expiration.
Ah gotcha, I can see that. Thank you!