How do i stop these login attempts ?

example


Nov 1 04:02:04 mybox vpopmail[18538]: vchkpw-pop3: vpopmail user not found root@:66.92.149.194
Nov 1 04:02:04 mybox vpopmail[18658]: vchkpw-pop3: vpopmail user not found root@:66.92.149.194
Nov 1 04:02:05 mybox vpopmail[18696]: vchkpw-pop3: vpopmail user not found root@:66.92.149.194
Nov 1 04:02:05 mybox vpopmail[18850]: vchkpw-pop3: vpopmail user not found root@:66.92.149.194
Nov 1 04:02:06 mybox vpopmail[19081]: vchkpw-pop3: vpopmail user not found root@:66.92.149.194
Nov 1 04:02:06 mybox vpopmail[19158]: vchkpw-pop3: vpopmail user not found admin@:66.92.149.194
Nov 1 04:02:06 mybox vpopmail[19271]: vchkpw-pop3: vpopmail user not found root@:66.92.149.194
Nov 1 04:02:06 mybox vpopmail[19305]: vchkpw-pop3: vpopmail user not found admin@:66.92.149.194
Nov 1 04:02:07 mybox vpopmail[19309]: vchkpw-pop3: vpopmail user not found root@:66.92.149.194
Nov 1 04:02:07 mybox vpopmail[19311]: vchkpw-pop3: vpopmail user not found admin@:66.92.149.194
Nov 1 04:02:07 mybox vpopmail[19315]: vchkpw-pop3: vpopmail user not found root@:66.92.149.194
Nov 1 04:02:07 mybox vpopmail[19317]: vchkpw-pop3: vpopmail user not found admin@:66.92.149.194
Nov 1 04:02:07 mybox vpopmail[19321]: vchkpw-pop3: vpopmail user not found root@:66.92.149.194
Nov 1 04:02:08 mybox vpopmail[19326]: vchkpw-pop3: vpopmail user not found root@:66.92.149.194


Nov 1 13:47:23 mybox vpopmail[30054]: vchkpw-smtp: vpopmail user not found inna@:114.44.115.56
Nov 1 13:47:33 mybox vpopmail[30055]: vchkpw-smtp: vpopmail user not found inna@:114.44.115.56
Nov 1 13:47:41 mybox vpopmail[30056]: vchkpw-smtp: vpopmail user not found inna@:114.44.115.56
Nov 1 13:47:49 mybox vpopmail[30057]: vchkpw-smtp: vpopmail user not found inna@:114.44.115.56
Nov 1 13:47:57 mybox vpopmail[30068]: vchkpw-smtp: vpopmail user not found inna@:114.44.115.56
Nov 1 13:48:04 mybox vpopmail[30129]: vchkpw-smtp: vpopmail user not found inna@:114.44.115.56
Nov 1 13:48:12 mybox vpopmail[30133]: vchkpw-smtp: vpopmail user not found inna@:114.44.115.56
Nov 1 13:48:19 mybox vpopmail[30136]: vchkpw-smtp: vpopmail user not found inna@:114.44.115.56
Nov 1 13:48:28 mybox vpopmail[30142]: vchkpw-smtp: vpopmail user not found inna@:114.44.115.56
Nov 1 13:48:36 mybox vpopmail[30146]: vchkpw-smtp: vpopmail user not found academia@:114.44.115.56
Nov 1 13:48:44 mybox vpopmail[30152]: vchkpw-smtp: vpopmail user not found academia@:114.44.115.56
Nov 1 13:48:52 mybox vpopmail[30161]: vchkpw-smtp: vpopmail user not found academia@:114.44.115.56
Nov 1 13:49:00 mybox vpopmail[30171]: vchkpw-smtp: vpopmail user not found academia@:114.44.115.56
Nov 1 13:49:07 mybox vpopmail[30174]: vchkpw-smtp: vpopmail user not found academia@:114.44.115.56

Got BFD but that does not seem to stop them, anyone got a rule to add
to ban the attempts

thanks

We had an issue where BFD was checking those maillogs but strangely was blocking genuine users as was counting some genuine logins within the count which was causing us many problems for a few days. We went the opposite way and removed auto BFD on the maillogs.

what do you use instead ?
just looking for something to ban the ip after so many login attempts

thank you for your reply