I am sorry to her that you are seeing issues with your trusted senders. Generally this ends up in the Junk E-Mail folder if the message fails either SPF or DKIM, both of theses are designed to help fight spoofing and so they are still processed, even on trusted senders.
Domain Administrators can add specific email addresses (such as firstname.lastname@example.org) or domains (such as example.com) that will be exempted from spam filtering. This can prevent mail from friends, business associates and mailing lists from being blocked and lets the system know that these messages come from a trusted source. Note: Email addresses in a user's contacts are always considered trusted senders. In addition, if users unmark a message as spam, the sender is automatically included on their personal trusted senders list.
Below is an example of the email header where the sender is a trusted sender AND passed both the DKIM and SPF checks.
X-SmarterMail-Spam: SPF_Pass, HostKarma - Whitelist, Reverse DNS Lookup [Passed], ISpamAssassin 0 [raw: 0], DK_Pass, DKIM_Pass
X-SmarterMail-TotalSpamWeight: 0 (Trusted Sender - Domain)
Here is n example of a trusted sender that failed either the DKIM or SPF checks.
X-SmarterMail-Spam: SPF_SoftFail, Reverse DNS Lookup [Passed], ISpamAssassin 7 [raw: 5], DK_None, DKIM_None
X-SmarterMail-TotalSpamWeight: 19 (Trusted Sender - User, failed SPF)
If you look at ( or post ) the header of the email you should see if it failed one of these checks. You can also review the Delivery logs to see if it failed any of these checks