For approved senders, we first verify the origin of the message, so that messages that are actually from spammers claiming to be the approved sender are correctly filtered.

Unfortunately, many senders do not provide adequate methods to verify the legitimacy of the message origin such as DMARC, SPF, and DKIM. Even those that do provide these authentication methods often unknowingly send emails that fail these verification checks.

So if you see a message that has been quarantined even though you marked the sender as an approved sender, it most likely means that we were unable to verify the source of the message. If you're sure the message is a legitimate message:

• First, double check that the message is not a phishing attempt or some other cleverly disguised malicious email. While clean email failing verification is actually quite common, it's even more common for spam and other malicious messages.
• Once you're absolutely certain that the message is clean, you have two options:
  • You can add an additional "approved source" for the sender. This is done by locating the message in the quarantine, and clicking the "approve sender" link. This will detect the source of the message, and add it as an approved sender to your approved sender once you click the "save" button on the dialog that appears.
  • You can choose to allow any messages claiming to be from the sender, regardless of the source. This is done by locating and clicking on the approved sender in the Settings > Approved Senders page, clicking the "Advanced" link, clicking the "Allow any messages claiming to be from this sender", and then clicking the "save" button. Warning: This opens your domain up to any attack from spammers that claim to be from the approved sender's address, as it disables all verification checks.