CheckDNSBLs checks if the given IP address is listed in any of the DNSBLs, and returns a decision, based on the results.

NewManager creates new SMTP server manager.

NewPlainAuthServer creates a new PLAIN authentication server.

BannedCode SMTP code.

DNSBLDefaultSignal is the default signal for DNSBLs.

DNSBLTimeout is the timeout for DNSBL requests.

GreylistCode SMTP code.

Incoming is the direction of the email.

NoUserCode SMTP code.

Outgoing is the direction of the email.

RBLCode SMTP code.

BannedEnhancedCode enhanced SMTP code.

DNSBLs is a list of Domain Name System Blacklists with list of signals they use.

ErrBanned returned to banned hosts.

ErrGreylisted returned when the host is graylisted.

ErrInvalidEmail for invalid emails :).

ErrNoUser returned when no such mailbox found.

ErrRBL returned when the host is blacklisted.

GreylistEnhancedCode is GraylistCode in enhanced code notation.

NoUserEnhancedCode enhanced SMTP code.

RBLEnhancedCode is RBLCode in enhanced code notation.

SMTP client.

DNSBLRequest is a request to check if an IP address is listed in any of the DNSBLs.

Listener that rejects connections from banned hosts.

PlainAuthServer is a server implementation of the PLAIN authentication mechanism.

Caller is Sendmail caller.