One of our customers reported that one of their emails had gone missing. First, we verified if the sender’s mail server was working perfectly and not holding that particular email in queue. Second, we checked the recipient’s Spam folder in their Webmail, because emails are often intercepted and moved to the Spam folder.
To help our customer understand why the email from that particular sender was marked as Spam, we gave them the following step-by-step guide:
First, go to the Spam folder in your Webmail
View the full header of the Spam-marked mail you wish to investigate further
The Couldmark Spam filtering system checks the sender’s email host for any incorrect configuration, previous spamming activities and any other things that makes this email suspicious.
To bypass this, check this out “Client host blocked?”