Hi, i’m trying configure my mail client do connect my VPS with my Mailcow, but receive error, but check the server, i see this error:
warning: hostname 191-255-240-58.dsl.telesp.net.br does not resolve to address 191.255.240.58: Name or service not known
warning: unknown[191.255.240.58]: SASL PLAIN authentication failed: (reason unavailable), sasl_username=xxx
This is my dynamic IP from my local ISP, how i resolve this ? why this occur ?
And after trying many times, i received this from netfilter log:
191.255.240.58 matched rule id 3 (warning: unknown[191.255.240.58]: SASL PLAIN authentication failed: (reason unavailable), sasl_username=xxx)
Banning 191.255.240.58/32 for 30 minutes
Thanks for all help.
Daniel