[8organicbits]

Last week I saw the same behavior sending email from my work's Google Workspace account to my personal Gmail account. The email stays within Google, I'm logged into both accounts on the same computer, does Google think I am I spamming myself...?

[77pt77]

Google's expense reimbursement emails were systematically considered to be SPAM by gmail.

Google knew this because they even issued warnings.

Still, using your own domain and machine is different.

Unless you've had an interaction with that email address it will be considered SPAM.