I am seeing this in the log:
 1 more attempts in the next 600 seconds until 219.128.55.254/32 is banned
netfilter-mailcow-1  | 45.148.10.35 matched rule id 3 (warning: unknown[45.148.10.35]: SASL LOGIN authentication failed: (reason unavailable), sasl_username=konica)
netfilter-mailcow-1  | 1 more attempts in the next 600 seconds until 45.148.10.35/32 is banned
netfilter-mailcow-1  | 45.148.10.29 matched rule id 3 (warning: unknown[45.148.10.29]: SASL LOGIN authentication failed: (reason unavailable), sasl_username=reception)
netfilter-mailcow-1  | 1 more attempts in the next 600 seconds until 45.148.10.29/32 is banned
netfilter-mailcow-1  | 112.15.84.229 matched rule id 3 (warning: unknown[112.15.84.229]: SASL LOGIN authentication failed: (reason unavailable), sasl_username=info@dccathome.com)
netfilter-mailcow-1  | 1 more attempts in the next 600 seconds until 112.15.84.229/32 is banned
netfilter-mailcow-1  | 45.148.10.34 matched rule id 3 (warning: unknown[45.148.10.34]: SASL LOGIN authentication failed: (reason unavailable), sasl_username=ftp)
netfilter-mailcow-1  | 1 more attempts in the next 600 seconds until 45.148.10.34/32 is banned
netfilter-mailcow-1  | 45.148.10.86 matched rule id 3 (warning: unknown[45.148.10.86]: SASL LOGIN authentication failed: (reason unavailable), sasl_username=testmail)
netfilter-mailcow-1  | 1 more attempts in the next 600 seconds until 45.148.10.86/32 is banned
netfilter-mailcow-1  | 45.148.10.39 matched rule id 3 (warning: unknown[45.148.10.39]: SASL LOGIN authentication failed: (reason unavailable), sasl_username=media)
netfilter-mailcow-1  | 1 more attempts in the next 600 seconds until 45.148.10.39/32 is banned
netfilter-mailcow-1  | 45.148.10.30 matched rule id 3 (warning: unknown[45.148.10.30]: SASL LOGIN authentication failed: (reason unavailable), sasl_username=abuse)
netfilter-mailcow-1  | 1 more attempts in the next 600 seconds until 45.148.10.30/32 is banned
netfilter-mailcow-1  | 45.148.10.69 matched rule id 3 (warning: unknown[45.148.10.69]: SASL LOGIN authentication failed: (reason unavailable), sasl_username=finance)
netfilter-mailcow-1  | 1 more attempts in the next 600 seconds until 45.148.10.69/32 is banned
netfilter-mailcow-1  | 45.148.10.44 matched rule id 3 (warning: unknown[45.148.10.44]: SASL LOGIN authentication failed: (reason unavailable), sasl_username=david)
netfilter-mailcow-1  | 1 more attempts in the next 600 seconds until 45.148.10.44/32 is banned
netfilter-mailcow-1  | 45.148.10.25 matched rule id 3 (warning: unknown[45.148.10.25]: SASL LOGIN authentication failed: (reason unavailable), sasl_username=office)
netfilter-mailcow-1  | 1 more attempts in the next 600 seconds until 45.148.10.25/32 is banned
netfilter-mailcow-1  | 45.148.10.36 matched rule id 3 (warning: unknown[45.148.10.36]: SASL LOGIN authentication failed: (reason unavailable), sasl_username=operator)
netfilter-mailcow-1  | 1 more attempts in the next 600 seconds until 45.148.10.36/32 is banned
netfilter-mailcow-1  | 45.148.10.31 matched rule id 3 (warning: unknown[45.148.10.31]: SASL LOGIN authentication failed: (reason unavailable), sasl_username=ceshi)
netfilter-mailcow-1  | 1 more attempts in the next 600 seconds until 45.148.10.31/32 is banned
netfilter-mailcow-1  | 45.148.10.37 matched rule id 3 (warning: unknown[45.148.10.37]: SASL LOGIN authentication failed: (reason unavailable), sasl_username=print)
netfilter-mailcow-1  | 1 more attempts in the next 600 seconds until 45.148.10.37/32 is banned
netfilter-mailcow-1  | 45.148.10.26 matched rule id 3 (warning: unknown[45.148.10.26]: SASL LOGIN authentication failed: (reason unavailable), sasl_username=proyecto)
netfilter-mailcow-1  | 1 more attempts in the next 600 seconds until 45.148.10.26/32 is banned
netfilter-mailcow-1  | 45.148.10.93 matched rule id 3 (warning: unknown[45.148.10.93]: SASL LOGIN authentication failed: (reason unavailable), sasl_username=alex)
netfilter-mailcow-1  | 1 more attempts in the next 600 seconds until 45.148.10.93/32 is banned
netfilter-mailcow-1  | 45.148.10.94 matched rule id 3 (warning: unknown[45.148.10.94]: SASL LOGIN authentication failed: (reason unavailable), sasl_username=system)
netfilter-mailcow-1  | 1 more attempts in the next 600 seconds until 45.148.10.94/32 is banned
netfilter-mailcow-1  | 45.148.10.89 matched rule id 3 (warning: unknown[45.148.10.89]: SASL LOGIN authentication failed: (reason unavailable), sasl_username=report)
netfilter-mailcow-1  | 1 more attempts in the next 600 seconds until 45.148.10.89/32 is banned
netfilter-mailcow-1  | 45.148.10.91 matched rule id 3 (warning: unknown[45.148.10.91]: SASL LOGIN authentication failed: (reason unavailable), sasl_username=training)
netfilter-mailcow-1  | 1 more attempts in the next 600 seconds until 45.148.10.91/32 is banned
netfilter-mailcow-1  | 45.148.10.90 matched rule id 3 (warning: unknown[45.148.10.90]: SASL LOGIN authentication failed: (reason unavailable), sasl_username=test3)
netfilter-mailcow-1  | 1 more attempts in the next 600 seconds until 45.148.10.90/32 is banned
netfilter-mailcow-1  | Blacklist was changed, it has 224 entries
netfilter-mailcow-1  | 45.148.10.59 matched rule id 3 (warning: unknown[45.148.10.59]: SASL LOGIN authentication failed: (reason unavailable), sasl_username=temp)
netfilter-mailcow-1  | 1 more attempts in the next 600 seconds until 45.148.10.59/32 is banned
Should I manually add 45.148.10.0/24 to the blacklist?