Configure IMAP and change SMTP settings to read Gmail messages in other mail clients, such as Microsoft Outlook and Apple Mail. When you use IMAP, you can read your Gmail messages on multiple devices, and the messages are synchronized in real time. You can also read Gmail messages using POP.

How does SMTP work?
Simply put, when you send an email from an email client, it is forwarded to the SMTP server. When it reaches the SMTP server, it is sent to the recipient's email server. SMTP essentially takes different parts of your message and categorizes them. This allows the other server to understand the message in a two-way communication using a set of standards.

We recommend enabling 2-step verification and generating an app password, which will then be used in the password field. When two-step verification is disabled, the Gmail account must be configured to allow less secure applications to access it.
If your organization's email is different from the sender's address in your email settings, outgoing emails may be limited or rejected on some SMTP servers. Note that the organization's email address is used in the From email header attribute (this will make the email appear to come from that organization's email address).
If your organization's email is different from the sender's address in the mailing settings (which is typical for email from a personal SMTP account), the delivery may fail on some SMTP servers.
The Gmail SMTP server may use a different address or alias (other than the username for that particular Gmail account) but that address needs to be configured in the user's Gmail settings. See the help article Sending emails from a different address or alias for more information. Otherwise, the From header attribute will be replaced by the username of the account user.

Personal Gmail accounts can send a maximum of 500 emails in a day and G Suite accounts can send a maximum of 2000 emails in a day. We recommend setting the Throttler settings to accommodate these limits.

https://www.not-working.co/gmail-smtp