Greylisting Settings

Greylisting is recommended for advanced users only. See here for more information.

Greylisting - greylisting
Enable or disable server wide greylisting. Greylisting will tell the mail server to temporarily reject any email from a sender it does not recognize. If the mail is legitimate, the originating server will try again after a delay, and if sufficient time has elapsed, the email will be accepted.
Default: false

Greylisting interval - grey_interval
A period of time that a sender should wait for before retrying sending the mail (in minutes).
Default: 5

Expire interval - expire_interval
A period of time after which a record in grey list expires (in minutes). The default expire interval is 36 days.
Default: 51840

Penalties - penalties
Enable or disable penalties. Penalties are a period of time added to the grey interval in case a sender retried sending mail before the grey interval finished (in minutes).
Default: false

Penalty interval - penalty_interval
A period of time added to the grey interval in case a sender retried sending mail before the grey interval finished (in minutes).
Default: false

Greylisting Whitelist

Whitelist a mail server from greylisting. Remember that you are whitelisting the remote hosts client rDNS record (PTR record) not an email address. Wildcard patterns are supported:

// whitelist a single mail server
mail.example.com

// whitelist all mail servers from a provider
*.example.com

Greylisting Blacklist

Blacklist a mail server from greylisting. Emails that are blacklisted will be listed under Warden -> Logs -> Reject Log. Blacklisted entries will have the a 451 4.7.1 status with the message Command rejected.

// matches mta-70-12-15.sparkpostmail.com
*[0-9][0-9]-[0-9][0-9]-[0-9][0-9]*

// matches any of the following keywords in the remote host like mail25.static.mailgun.info
dynamic|static|ppp|dyn-ip|dial-up