athena% add sipb; pop
pop: connect
pop: stat [sends STAT command]
3 messages, 8136 bytes.
pop:  list [sends LIST command]
message	size
1	1743
2	1349
3	5044
pop:  retr 1
Received: from PACIFIC-CARRIER-ANNEX.MIT.EDU by po10.MIT.EDU 
[...]
pop: dele 1 [marks message 1 to be deleted on server]
pop: quit [server actually deletes 1 and closes connection]