Looking up the IP:
Search results for: 69.20.61.210
OrgName: Rackspace.com
OrgID: RSPC
Address: 112 E. Pecan St.
Address: Suite 600
City: San Antonio
StateProv: TX
PostalCode: 78205
Country: US
OrgAbuseHandle: ABUSE45-ARIN
OrgAbuseName: Abuse Desk
OrgAbusePhone: +1-210-892-4000
OrgAbuseEmail: (e-mail address removed)
This IP seems to be a web hosting company.
Plugging the IP into a browser brings up an "under construction" page.
http://www.rackspace.com is the main URL.
I'd give a shot at the abuse address to stop the useless bandwidth and
block the request.
Under Administration in Kerio the highest setting will block all
unknown and not bother you with the pesky request boxes that popup
each time some stray request lands at your door step.