I undersand

Received two calls from the number, both were in the late morning/early afternoon.  My telephone management system flagged the calls as spam and sent them directly to voicemail.  Each time, they left messages, both of which were pretty much silent, except for what sounded like keyboards clicking the background.

Received 4 calls from this number in 3 consecutive days.  Picked up the last two times and there was only silence on the other end.  Searched number and related to 1and1.com.  In the previous week, I had received a letter from 1and1.com saying my card or paypal has blocked some payment and that they had been trying to reach me, but (1) the phone calls didn't begin until AFTER the letter, (2) I have never purchased any service or product from 1and1, and (2) never had a website through anybody, so appears to be a scam.

Unwanted calls.
610-560-1621

1&1 Internet