Postfix settings wrong? [closed]

I can't get Postfix to send an email from the CMD via Gmail SMTP on Raspbian Buster Lite.

I will refer as sss@gmail.com to the sending mail and rrr@gmail.com to the receiving one.

I tried to configure Postfix according to different guides, including this one and this one, without being able to make it work.

Here's my settings:

• sudo dpkg-reconfigure postfix

• /etc/postfix/main.cf

(I was forced to insert those 2 in 3rd party services because it was recognized as spam by the editor)

• /etc/postfix/sasl/sasl_passwd

[smtp.gmail.com]:587 sss@gmail.com:<pw generated via Google security settings>

Launching

sudo systemctl restart postfix

then

echo "Test mail" | mail -s "This is a test mail" rrr@gmail.com

and then

sudo tail -f /var/log/mail.log

I get the following error messages:

Nov  4 19:31:01 SmartBerry postfix/cleanup[28706]: 7227C5E5F1: message-id=<20191104183101.7227C5E5F1@example.com>
Nov  4 19:31:01 SmartBerry postfix/bounce[28712]: 6C8275E5EC: sender non-delivery notification: 7227C5E5F1
Nov  4 19:31:01 SmartBerry postfix/qmgr[28661]: 7227C5E5F1: from=<>, size=2648, nrcpt=1 (queue active)
Nov  4 19:31:01 SmartBerry postfix/qmgr[28661]: 6C8275E5EC: removed
Nov  4 19:31:01 SmartBerry postfix/local[28711]: 7227C5E5F1: to=<root@example.com>, relay=local, delay=0.02, delays=0.01/0/0/0.01, dsn=5.2.0, status=bounced (cannot update mailbox /var/mail/root for user root. unable to create lock file /var/mail/root.lock: Too many levels of symbolic links)
Nov  4 19:31:01 SmartBerry postfix/qmgr [28661]: 7227C5E5F1: removed

I'm pretty sure it's caused by a bad Postfix reconfiguration, but I can't figure out how to fix it. Thanks for your time :)