Why is my Gmail SMTP settings not working?

Configure IMAP and change Gmail 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.

What are the Gmail SMTP settings? That is an easy question.

Gmail is a great webmail app, but some people find it more convenient to access their own inbox from an email client like Thunderbird or Outlook - this requires setting up your outgoing server by entering the correct settings.
First, open the configuration panel of the mail software:
and fill in the fields with the Gmail SMTP server settings, which are:

• Gmail SMTP server name: smtp.gmail.com
• Gmail SMTP username: your Gmail address
• Gmail SMTP password: your password
• Gmail SMTP port: 465

You can then choose your security and authentication options - for more information, see our article on SMTP settings. (And of course you can also use Gmail's POP details to receive emails.)

However, remember that Gmail's SMTP comes with severe sending limits to prevent spammers from using your outgoing server to delete junk emails. The limit is 100 recipients at a time and 500 messages per day: if you cross this restriction, your account will be blocked by Google.

In addition, your SMTP server is based on shared IPs that cannot guarantee you full deliver ability, as they can also be used by spammers who seriously damage your reputation, thus increasing the possibility that your legitimate email will also be filtered by anti-spam systems. 

SMTP Settings - How to Customize SMTP Settings

SMTP stands for Simple Mail Transfer Protocol and is a set of commands used to authenticate and direct the transfer of email from one server to another. Your MINDBODY site is configured to send all automated emails from Business <siteID> @ mindbodyonline.com by default.

However, it's easy to customize your SMTP so that your automated emails come from an email address of your choice. Not only does this mark emails with an address that your customers recognize, but the more personalized your emails are, the better they should be at getting past your customers' spam filters.

Gmail SMTP Settings
Security settings

You must change the security settings of your Gmail account from which you want to send email.

Here are the steps to change your Gmail account security settings:

• Go to your Gmail account settings (gear icon) as shown in the image below and click on Other Google Account Settings.
• Now click on Security in the left menu as shown in the following image:
• Then click Turn on access (not recommended) to access less secure applications.
• Click to activate the highlighted area in the image below:
• Now you will be able to send the email using Gmail's SMTP server without any error.
• It's about reducing the security settings in Gmail.