Sending email from GMail protocol I'm using AM Forms on a site that I've built. The site is now in production.

Via the AM Forms notifications settings, the email I've entered for Email recipients and Sender email address notification email is an email which is hosted with G Suite.

Am I correct in thinking that these notifications are being sent via Craft's email settings (currently PHP Mail)? 

G Suite is running DKIM, SPF and DMARC, so the PHP Mail protocol is not the best method for receiving these notifications. If I change Craft's email protocol to GMail, how safe are the credentials I enter and are they encrypted?
Am I correct in thinking that these notifications are being sent via Craft's email settings (currently PHP Mail)?


Probably.  There are plenty of other reasons to not use PHP Mail on a production environment, though.


  If I change Craft's email protocol to GMail, how safe are the credentials I enter and are they encrypted?


If you select the "GMail" as an email delivery method in Craft, Craft sets the SMTP hostname to smtp.gmail.com, forces SMTP authentication over SSL over port 465 and passes in the given username/password.

No encryption is done because SSL is used, so the credentials are as safe as SSL is.