Incoming emails from my customers emails are being tagged as "Spam". How can I stop this?

Email & Webmail
There are 2 ways to help with this.
  1. In web mail, right click on the email and select "Not Spam".  This add that senders address to your Trusted Senders list so that future emails from that address will be delivered without spam-checking, and it will help to teach the email server what is "good" and what is "bad" email.
  2. Add that address to your "Trusted Senders" list.  To do that
    1. Log in to web mail
    2. Click on the "Settings" icon in the menu at the top of the page
    3. Click on "Trusted Sender" icon in the tree on the LHS of the page
    4. Add the address to the box
    5. Save your changes