When attempting to claim a user seat and reset their password, the user is not receiving a password reset email, so they cannot change their password and log into their Outreach user seat.
Contact Outreach Support via the Support Portal and request that this team assist directly.
Please note: if your organization uses an SSO tool to access Outreach, you cannot request a password reset through Outreach, one will never be sent. If you use an SSO tool and cannot access your Outreach instance, you need to contact your SSO Administrators, not Outreach Support, who cannot assist here.
The most common cause for password reset emails not being sent is that the recipient's mailbox has been suppressed from receiving automated messaging from Outreach. This is quite rare, but it can happen if a users' mailbox returns a bounce notification to a message sent by Outreach, (usually, because the mail server is offline for temporary maintenance,) at which point no further automated messaging will be sent to this user. Outreach Support needs to remove this mailbox from this suppression list and manually send a claim link to the user in question.