# Functions
IsPermFail returns true if the error returned by Verify is a permanent failure.
IsTempFail returns true if the error returned by Verify is a temporary failure.
NewSigner creates a new signer.
Sign signs a message.
Verify checks if a message's signatures are valid.
VerifyWithOptions performs the same task as Verify, but allows specifying verification options.
# Constants
DNS TXT resource record (RR) lookup algorithm.
# Variables
ErrTooManySignatures is returned by Verify when the message exceeds the maximum number of signatures.
# Structs
Signer generates a DKIM signature.
SignOptions is used to configure Sign.
A Verification is produced by Verify when it checks if one signature is valid.
VerifyOptions allows to customize the default signature verification behavior.
# Type aliases
Canonicalization is a canonicalization algorithm.
QueryMethod is a DKIM query method.