Use:

~smtpclientblocks~
<format string>
~end~

The format string can have the replacements

• address - IP address (returned as host address or CIDR address as appropriate)
• date - the date/time the address was added to the database in YYYYMMDDHHMMSS format
• expiry - the date/time the address is set to expire in YYYYMMDDHHMMSS format
• reason - the user who added the address or 'auto' if the block was added by VPOP3 automatically

Note that this only returns the blocks which have not yet expired. The database stores blocks for 30 days after expiry as a basic audit trail, those can only be accessed from the database directly.