Unknown Imap Logouts in Logwatch

Hi,

I'm a novice at reading the logwatch results but I was alarmed at seeing a few LOGOUT IPs that were not like the rest. Usually everything is either me or another couple of users. Here's a sample:

Known user:
LOGOUT, user=known@myhost.com, ip=[::ffff:67.188.132.183], headers=5306, body=171623, rcvd=20284, sent=231499, time=68502: 1 Time(s)
LOGOUT, user=knownuser@myhost.com, ip=[::ffff:67.188.132.183], headers=5830, body=216964, rcvd=17809, sent=300830, time=68501: 1 Time(s)

Unknown IP
LOGOUT, ip=[::ffff:69.64.32.77], rcvd=11, sent=307: 48 Time(s)
LOGOUT, ip=[::ffff:81.19.151.110], rcvd=11, sent=307: 48 Time(s)
LOGOUT, ip=[::ffff:85.25.129.25], rcvd=11, sent=307: 43 Time(s)

These IPs all resolve to web pages.

Should I be concerned about these?

Thanks

 

No customers from germany but I do use an uptime monitor. Would this show up in the logs even if someone just contacts the IMAP?

Thanks