Aanpassen van wachtwoord is altijd verstandig.
Dit is misschien handig om te lezen voor je hostingprovider:
USAGE WARNING
We're getting a lot of reports of spurious blocking caused by sites using the CBL to block authenticated access to smarthosts / outgoing mail servers.
THE CBL is only designed to be used on INCOMING mail, i.e. on the hosts that your MX records point to.If you use the same hosts for incoming mail and smarthosting, then you should always ensure that you exempt authenticated clients from CBL checks, just as you would for dynamic/dialup blocklists.
Another way of putting this is:
"Do not use the CBL to block your own users".