Bummer. Guess you're not welcome..
Jk, happens all the time. It's the pitfall of the ultra short domain name we chose 75f.io. Gets flagged as spam all the time and gets caught in junk, spam, clutter, and quarantines fairly regularly. Something we are working on.
To fully setup your account you will need to receive an OTP (one time passcode) to your email. But in my experience, the OTP email is much less likely to get caught in your quarantine. If it does, you may need to reach out to your IT department and let them know to check for emails coming inbound from 75f.io domains.