USA: 

There are two main postage types in US 

1. First class - 1 to 3 business days - First class mail is typically used for transactional mail purposes like invoices, bills and so on which requires quicker SLA and has higher sensitivity with regards to data and content 

First class is comparatively priced higher to standard mail rates however compensated for quicker delivery times. 

2. Standard Class - Locally - Under 5 days 

Nationally - Anywhere between 2 to 3 weeks 

Standard class mailing is more apt for marketing or direct mail that do not require quick SLA or delivery time commitments. 

Standard mailing would qualify for a cheaper per piece rate however there is a minimum requirement of sending at least 200 pieces of the same collateral type. 

Canada: 

There are two main type of postage type in Canada

1. Lettermail - https://www.canadapost-postescanada.ca/cpc/en/support/articles/lettermail/overview.page

Lettermail Delivery Times 

2 Business days Locally 

3 Business days within a province and 

4 Business days nationally 

2. Personalised mail - 

https://www.canadapost-postescanada.ca/cpc/en/support/articles/when-to-say-yes/whats-personalized-mail.page?

Personalised Delivery Times 

3 Business days locally 

3-5 Business days within a province and 

4-8 days nationally 

To qualify as Personalized Mail service, mailings must:

Include a minimum of 100 items of the same collateral type.