Settings for the common providers

Choosing the service in Mail > Connection fills these values in. The table is here for when you set them by hand.

Service	Server	Port / encryption	Password
Gmail / Google Workspace	smtp.gmail.com	587 TLS	An app password (Google account > Security > App passwords), not your normal one
Microsoft 365 / Outlook	smtp.office365.com	587 TLS	SMTP authentication must be on for the mailbox; with two-step verification, an app password
Brevo	smtp-relay.brevo.com	587 TLS	An SMTP key from SMTP & API
Mailgun	smtp.mailgun.org (EU: smtp.eu.mailgun.org)	587 TLS	The SMTP credentials of your sending domain
SendGrid	smtp.sendgrid.net	587 TLS	Username apikey, password your API key
Amazon SES	email-smtp.<region>.amazonaws.com	587 TLS	The SMTP credentials created in SES
Aruba	smtps.aruba.it	465 SSL	The mailbox password
Register.it	authsmtp.securemail.pro	465 SSL	The mailbox password
OVHcloud	ssl0.ovh.net	465 SSL	The mailbox password

To keep the password out of the database, add define( 'NOPDML_SMTP_PASSWORD', '...' ); to wp-config.php: Mail uses it and the password field shows that it is set there.