Issue Description
You are sending password reset links, but not receiving those emails, or you are trying to login with what you thought was the correct login without having success.
Issue Resolution
By default, the Marketo login is an email address. If you needed to reset password for a User, you enter the login which happens to be the email address associated.
However, there is a feature that separates the login and email address, where the login could be test@test.com, but the associated email address for this login is your.name@company.com. If this feature is enabled and you needed to reset a password, you would still enter the login (test@test.com) and the reset password email would be sent to the associated email address (your.name@company.com).
If you would like the feature that allows for separate login and email addresses, please contact Marketo Support.