DOMAINS for which this host should accept mail via SMTP. This GENERALLY contains all of the domains in locals, as well as any virtual domains and any domains for which this host is a backup mail server. If rcpthosts does not exist, qmail ACCEPTS and delivers mail for any domain, a severe MISCONFIGURATION known as an "open relay," which will be hijacked by spammers. Be sure your rcpthosts file exists before starting qmail. If you haven't defined any virtual domains, just copy locals to rcpthosts.

Domains for which this host should accept mail via SMTP. This generally contains all of the domains in locals, as well as any virtual domains and any domains for which this host is a backup mail server. If rcpthosts does not exist, qmail accepts and delivers mail for any domain, a severe misconfiguration known as an "open relay," which will be hijacked by spammers. Be sure your rcpthosts file exists before starting qmail. If you haven't defined any virtual domains, just copy locals to rcpthosts.