How to Add an Inbox for Sending

Inboxes in QuickMail

Inboxes in a QuickMail account are the email addresses that QuickMail will use to send messages from and monitor replies in.
QuickMail allows users to add as many Inboxes as they need.
Each inbox has its own identity so sending emails from different persons in the same account is possible. 
Having multiple inboxes is also a good way to spread out the volume of messages coming from a single campaign.
To add an Inbox to QuickMail, head to Settings > Inboxes.
Click the Add Inbox button, and you'll be presented with two options. I have access to the Inbox and I don't have access to the Inbox.
If you have access to the Inbox, click Continue on the corresponding button, and you'll be presented with the three types of Inboxes QuickMail supports: Google, Microsoft, or a Custom Inbox. 
Google is for G Suite inboxes, Microsoft is for Outlook 365 or Microsoft-hosted Exchange accounts, and Custom is for any Inbox that you have SMTP and IMAP credentials for. 
If you're using a Google or Microsoft inbox, you'll be taken to their authentication page, and you can complete the steps from there.
If you don't have access to the Inbox—in the case of working with a client, for instance, use the corresponding Continue button when adding the Inbox.
You'll be presented with a link to send to someone who does have access to the Inbox, and they'll see a page that looks like this:
From there, they'll be able to log in to their email account and allow your QuickMail account to access the client's email account.

Looking to add more inbox seats? Check this out - How to Add Additional Inboxes