heartcombo--devise/app/views/devise/mailer/unlock_instructions.html.erb

<p>Hello <%= @resource.email %>!</p>

<p>Your account has been locked due to an excessive amount of unsuccessful sign in attempts.</p>

<p>Click the link below to unlock your account:</p>

<p><%= link_to 'Unlock my account', unlock_url(@resource, :unlock_token => @resource.unlock_token) %></p>