To allow the domain administrator to remain in control over the filtering, it's possible to whitelist/blacklist a sender.
Sender whitelist
All filtering checks are disabled for whitelisted senders. You can whitelist a specific sending email address, or a full sending domain. We recommend only using the sender whitelist if the system would otherwise wrongly block email from a certain sender. Spammers often use fake senders matching the recipient domain, or domains the recipient may have received emails from before, to try and bypass the filtering in that way. In addition, if the system is generally wrongly blocking a sender, you can always contact our customer support so we can research what problem is causing the rejection and resolve that issue.
Sender blacklist
Emails from senders listed on the blacklist will be automatically rejected. The messages are NOT quarantined. The messages are rejected with a 5xx SMTP error code, so legitimate sending SMTP servers will generate a bounce message to the sender.
Special usage
You can whitelist/blacklist a specific sending email address, or a full sending domain. To whitelist/blacklist all senders from a domain, you should only enter the domain (without *@).
