Stopping Spam Tickets (email connector)

We seem to get loads of spam on our support@ email account thats linked to CommitCRM. How can we just block it? Theres so many?

What email service providers do you guys use for the email connector?
Thanks

We use office365 and haven't had any issues.

Mailprotector is awesome and has some fantastic extra features for continuity, compliance, archiving and encryption.