Other SMTP security

Hi,

I am looking at the options with the plugin. Two questions:

I see the Other SMTP setup and it looks like that one can add the credentials of an email account here with the SMTP host. It looks simple, without all the hassle of all the other subscribed options but, is that a savvy way to do it. Does this not just put all this data into the WordPress database and is it secure. Would it be best to avoid this option with preference to the others?

Can you set up a gmail email address to work with the sendinblue option?