Issue symptoms
When I create new agents in Zendesk, they don't receive a welcome email.
Resolution steps
This is the expected behavior if Also send a welcome email when a new user is created by an agent or administrator isn't enabled in Admin Center > 
People > Configuration > End users. This setting applies to both agents and end users.
If you don't want to send a welcome email to all new agents and end users, leave this setting turned off, then resend the verification email to individual agents after you create them.
For more information, see these articles: